Amended answer
After examining the layout sketch added, and some other information surfacing, several paths to a solution become available.
The question is many-parts.
Dealing with the first part, an ornamental frame, we have:
(1) eso-pic package, and drawing on the PDF picture background layer (adapting @user11232 solution at ornaments in pgfornament to be at the corners at every page)
(2) background package (which runs on top of TikZ), and drawing a tikzpicture (adapting @GonzaloMedina solution at the same link as above)
(3) picture mode, and making a zero-width picture and placing it in the footer using fancyhdr package (Thanks to @BarbaraBeeton for the link to the Peter Wilson 2011 TUGboat article v32 p202).
As to the second matter, the question how many ornamental glyphs should go along an edge, aside from it being a judgemental/opinion-based question, an automatic solution (or solutions) could be designed and built (using some set of as-yet unspecified aesthetic rules), but, since the definition is only ever done once, manually implementing it is much more practical (and simpler).
For example, because \pgfornamentline can take a scale= option, thus making the number of ornaments discretionary according to taste, the ratio of the long:short edges of the page can be used as a guideline (or not): 5:3 (left:top) for A4 portrait, say; or 2:3 (left:top) for A5 landscape.
An automated solution sounds desirable and a method like this would involve tracking three dimensions, the page-edge ratio, the ornament scale factor, and the ornament height/width ratio, keeping two of them constant while varying the third, but won't be pursued further here (at least not tonight, anyway).
So:
The Frame
(1)eso-pic package drawing on the background layer with \AddToShipoutPictureBG.
Positioning and layout is manual.
The ornament line is assembled, so individual items are accessible (although, an assembled set of elements could be fed in, and repeated once only).
For completeness, for a version with an on/off switch for the frame, see (1a).

MWE
\documentclass[12pt]{article}
\usepackage{pgfornament}
\usepackage{eso-pic}
\usepackage{rotating}
\usepackage{xcolor}
\usepackage{lipsum}
\newcommand\AtPageUpperRight[1]{\AtPageUpperLeft{%
\put(\LenToUnit{\paperwidth},\LenToUnit{0\paperheight}){#1}%
}}%
\newcommand\AtPageLowerRight[1]{\AtPageLowerLeft{%
\put(\LenToUnit{\paperwidth},\LenToUnit{0\paperheight}){#1}%
}}%
\newcommand\ornscale{0.42}
\newcommand\ornscalev{0.44}
\newcommand\leavesthree{\pgfornament[scale=\ornscale]{87}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\pgfornament[scale=\ornscale]{87}}
\newcommand\leavesfive{\turnbox{-90}{\pgfornament[scale=\ornscalev]{87}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\pgfornament[scale=\ornscalev]{87}}}
\AddToShipoutPictureBG{%
\AtPageUpperLeft{\put(25,-50){\textcolor{blue}{\pgfornament[width=1.75cm]{61}}}}
\AtPageUpperRight{\put(-75,-50){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=v]{61}}}}
\AtPageLowerLeft{\put(25,50){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=h]{61}}}}
\AtPageLowerRight{\put(-75,50){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=c]{61}}}}
\AtPageUpperLeft{\put(78,-25){\leavesthree}}%top border
\AtPageLowerLeft{\put(78,27){\leavesthree}}%bottom
\AtPageUpperLeft{\put(25,-78){\leavesfive}}%left side
\AtPageUpperRight{\put(-25,-78){\leavesfive}}%right side
}
\begin{document}
\lipsum[1-40]
\end{document}
(1a)
To make the frame switchable on/off, create a new IF variable:
\newif{\ifbgoff}
\bgofftrue
where (in this methodology) true will mean "no frame" (as in "background off").
Add the if-condition to the \AddToShipoutPictureBG command like so:
\AddToShipoutPictureBG{%
\ifbgoff\else *<existing code>* \fi}
Usage: Toggle the frame on (with \bgofffalse)/off (with \bgofftrue) in conjunction with a \newpage or equivalent.
\begin{document}
\section{Off}
\lipsum[1-15]
\bgofffalse
\section{On}
\lipsum[1-15]
\newpage
\bgofftrue
\section{Off Again}
\lipsum[1-8]
\newpage\bgofffalse
\section{On Again}
\lipsum[1-15]
\newpage
\bgofftrue
\section{And Off Once More}
\lipsum[1-8]
\end{document}
Full MWE:
\documentclass[12pt]{article}
\usepackage{pgfornament}
\usepackage{eso-pic}
\usepackage{rotating}
\usepackage{xcolor}
\usepackage{lipsum}
\newcommand\AtPageUpperRight[1]{\AtPageUpperLeft{%
\put(\LenToUnit{\paperwidth},\LenToUnit{0\paperheight}){#1}%
}}%
\newcommand\AtPageLowerRight[1]{\AtPageLowerLeft{%
\put(\LenToUnit{\paperwidth},\LenToUnit{0\paperheight}){#1}%
}}%
\newcommand\ornscale{0.42}
\newcommand\ornscalev{0.44}
\newcommand\leavesthree{\pgfornament[scale=\ornscale]{87}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\pgfornament[scale=\ornscale]{87}}
\newcommand\leavesfive{\turnbox{-90}{\pgfornament[scale=\ornscalev]{87}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\pgfornament[scale=\ornscalev]{87}}}
\newif{\ifbgoff}
\bgofftrue
\AddToShipoutPictureBG{%
\ifbgoff\else \AtPageUpperLeft{\put(25,-50){\textcolor{blue}{\pgfornament[width=1.75cm]{61}}}}
\AtPageUpperRight{\put(-75,-50){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=v]{61}}}}
\AtPageLowerLeft{\put(25,50){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=h]{61}}}}
\AtPageLowerRight{\put(-75,50){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=c]{61}}}}
\AtPageUpperLeft{\put(78,-25){\leavesthree}}%top border
\AtPageLowerLeft{\put(78,27){\leavesthree}}%bottom
\AtPageUpperLeft{\put(25,-78){\leavesfive}}%left side
\AtPageUpperRight{\put(-25,-78){\leavesfive}}%right side
\fi}
\begin{document}
\section{Off}
\lipsum[1-15]
\bgofffalse
\section{On}
\lipsum[1-15]
\newpage
\bgofftrue
\section{Off Again}
\lipsum[1-8]
\newpage\bgofffalse
\section{On Again}
\lipsum[1-15]
\newpage
\bgofftrue
\section{And Off Once More}
\lipsum[1-8]
\end{document}
(2) background package plus tikzpicture in the \backgroundsetup command.
Positioning elements is much easier with TikZ.
The ornament line is a unit.
Backgrounds can be switched on/off or changed within the document on a page(s) basis.

MWE
\documentclass[12pt]{article}
\usepackage{background}
\usepackage{pgfornament}
\usepackage{lipsum}
\usetikzlibrary{calc}
\backgroundsetup{
scale=1,
opacity=1,
angle=0,
color=black,
contents={%
\begin{tikzpicture}[every node/.style={inner sep=0pt}]
\nodeshift={(1cm,-1cm)},anchor=north west
at (current page.north west) {\pgfornament[width=1.75cm]{61}};
\nodeshift={(-1cm,-1cm)},anchor=north east
at (current page.north east) {\pgfornament[width=1.75cm,symmetry=v]{61}};
\nodeshift={(1cm,1cm)},anchor=south west
at (current page.south west) {\pgfornament[width=1.75cm,symmetry=h]{61}};
\nodeshift={(-1cm,1cm)},anchor=south east
at (current page.south east) {\pgfornament[width=1.75cm,symmetry=c]{61}};
\pgfornamentline{CNW.north east}{CNE.north west}{3}{87}
\pgfornamentline{CSW.south east}{CSE.south west}{3}{87}
\pgfornamentline{CNW.south west}{CSW.north west}{5}{87}
\pgfornamentline{CNE.south east}{CSE.south east}{5}{87}
\end{tikzpicture}%
}
}
\begin{document}
\lipsum[1-40]
\end{document}
(3) a picture mode zero-width picture in the footer (or header, if desired)
Picture mode is used, so positioning is manual here.
Footers and headers (and associated pagestyles) can be modified using fancyhdr package commands.

MWE
\documentclass[12pt]{article}
\usepackage{pgfornament}
%\usepackage{eso-pic}
\usepackage{rotating}
\usepackage{xcolor}
\usepackage{fancyhdr}
\pagestyle{fancy}
\usepackage{lipsum}
\newcommand\ornscale{0.39}
\newcommand\ornscalev{0.45}
\newcommand\leavesthree{\pgfornament[scale=\ornscale]{87}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\pgfornament[scale=\ornscale]{87}}
\newcommand\leavesfive{\turnbox{-90}{\pgfornament[scale=\ornscalev]{87}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\textcolor{red}{\pgfornament[scale=\ornscale]{87}}\pgfornament[scale=\ornscalev]{87}}}
%\pgfornament[width=2cm]{3}
\newcommand{\upit}[2]{\raisebox{#1}{#2}}\newcommand{\rotpi}[1]{\rotatebox{180}{#1}}\newcommand{\rotrt}[1]{\rotatebox{90}{#1}}\newcommand{\rotlft}[1]{\rotatebox{-90}{#1}}
%%% draws a (page) frame
\newcommand*{\goddfoot}{\begin{picture}(0,0)
%\wb{10pt}{10pt}
\put(-70,-50){% change these to move the frame
\begin{picture}(0,0)
\multiput(52,0)(0,0){1}{\leavesthree} % bottom
\multiput(5,669)(0,0){1}{\leavesfive} % left
\multiput(530,669)(0,0){1}{\leavesfive} % right
\multiput(52,718)(0,0){1}{\leavesthree} % top
\put(0,700){\textcolor{blue}{\pgfornament[width=1.75cm]{61}}}%TL
\put(485,700){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=v]{61}}}%TR
\put(0,20){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=h]{61}}}%BL
\put(485,20){\textcolor{blue}{\pgfornament[width=1.75cm,symmetry=c]{61}}}%BR
\end{picture}}
\end{picture}}
\let\gevenfoot\goddfoot
\fancyfoot[L]{\goddfoot}
\begin{document}
\lipsum[1-40]
\end{document}
Original answer
You need to supply a Minimum Working Example so people can test their answers against without having to guess anything; and also use the remember picture,overlay options (as the manual says).
I am not sure what you intend the anchors for.
This MWE:
\documentclass{article}
\usepackage{tikz}
\usepackage{pgfornament}
\begin{document}
\begin{tikzpicture}[remember picture,overlay,every node/.style={inner sep=0pt}]
\node [shift={(1cm,-1cm)},blue,scale=2] (CNW)
at (current page.north west) {\pgfornament[height=1cm,width=1cm]{61}};
\node [shift={(-1cm,-1cm)},blue,scale=2] (CNE)
at (current page.north east) {\pgfornament[height=1cm,width=1cm,symmetry=v]{61}};
\node [shift={(1cm,1cm)},blue,scale=2] (CSW)
at (current page.south west) {\pgfornament[height=1cm,width=1cm,symmetry=h]{61}};
\node [shift={(-1cm,1cm)},blue,scale=2] (CSE)
at (current page.south east) {\pgfornament[height=1cm,width=1cm,symmetry=c]{61}};
\pgfornamentline[color=brown]{CNW}{CNE}{2}{87}
\pgfornamentline{CSW}{CSE}{2}{87}
\pgfornamentline{CNW}{CSW}{3}{87}
\pgfornamentline{CNE}{CSE}{3}{87}
\end{tikzpicture}%
produces this:

Addition
In TikZ, there are multiple ways to achieve the same effect.
If I understand the statement in the comments correctly, if the goal is to draw ornamental lines between the corners of a page, from corner to corner, and such that the centre of the line is on the page edge, then one way is -- to draw ornamental lines between the corners of the page:
\pgfornamentline[color=brown]{current page.north west}{current page.north east}{2}{87}
\pgfornamentline{current page.south west}{current page.south east}{2}{87}
\pgfornamentline{current page.north west}{current page.south west}{3}{87}
\pgfornamentline{current page.north east}{current page.south east}{3}{87}
To avoid being overwritten, (one method is) the corner ornaments can be pushed out of the way with the anchor= options.

MWE2
\documentclass{article}
\usepackage{tikz}
\usepackage{pgfornament}
\begin{document}
\begin{tikzpicture}[remember picture,overlay,every node/.style={inner sep=0pt}]
\node [shift={(1cm,-1cm)},blue,scale=2,anchor=north west] (CNW)
at (current page.north west) {\pgfornament[height=1cm,width=1cm]{61}};
\node [shift={(-1cm,-1cm)},blue,scale=2,anchor=north east] (CNE)
at (current page.north east) {\pgfornament[height=1cm,width=1cm,symmetry=v]{61}};
\node [shift={(1cm,1cm)},blue,scale=2,anchor=south west] (CSW)
at (current page.south west) {\pgfornament[height=1cm,width=1cm,symmetry=h]{61}};
\node [shift={(-1cm,1cm)},blue,scale=2,anchor=south east] (CSE)
at (current page.south east) {\pgfornament[height=1cm,width=1cm,symmetry=c]{61}};
%\pgfornamentline[color=brown]{CNW}{CNE}{2}{87}
%\pgfornamentline{CSW}{CSE}{2}{87}
%\pgfornamentline{CNW}{CSW}{3}{87}
%\pgfornamentline{CNE}{CSE}{3}{87}
\pgfornamentline[color=brown]{current page.north west}{current page.north east}{2}{87}
\pgfornamentline{current page.south west}{current page.south east}{2}{87}
\pgfornamentline{current page.north west}{current page.south west}{3}{87}
\pgfornamentline{current page.north east}{current page.south east}{3}{87}
\end{tikzpicture}%
%\begin{tikzpicture}[bullet/.style={%
%circle,draw,fill=black!30,inner sep=2pt}]
%\draw [help lines,color=black!60] (0,0) grid (5,2);
%\node[bullet] (A) at (0,0) {}; \node[bullet] (B) at (6,4) {};
%\pgfornamentline[color=red]{A}{B}{4}{88}
%\end{tikzpicture}
\end{document}
\pgfornamentline{start-pos}{finish-pos}number-of-repeats{ornament-number}e.g.,\pgfornamentline{CNW}{CNE}1{87}– Cicada Jan 12 '21 at 10:45