In order to rotate and shift you need only one of the answers to this question for the rotation, and add a shift. To the best of my knowledge both answers work fine.
However, one may want to go another way. One of the answers does not allow the user to accumulate transformations. The other answer does that, but at the expense of keeping track of the rotation matrix. This works fine as long as the user does not add further transformations by other means. So here is a third approach in which the current basis vectors get used to allow the user to stack transformations. The keys introduced are rotate about x axis and so on. Crucially, they do not rely on tikz-3dplot, they also work if you use the 3d view of the perspective library1, say. These preparations allow you to do something like
\begin{scope}[rotate about x axis=-20,canvas is xy plane at z=0,
shift={(O')}]
%Circle in transformed xy plane at z=0
\path[fill=red!40!white, draw=black] circle[radius=1cm];
\end{scope}
Full code:
\documentclass[tikz,border=3mm]{standalone}
\usepackage{tikz-3dplot}
\usetikzlibrary{arrows.meta}
\makeatletter
\def\tikz@td@retrieve@current@basis{%
\pgfmathsetmacro{\tikz@td@currentxx}{\pgf@xx/1cm}%
\pgfmathsetmacro{\tikz@td@currentxy}{\pgf@xy/1cm}%
\pgfmathsetmacro{\tikz@td@currentyx}{\pgf@yx/1cm}%
\pgfmathsetmacro{\tikz@td@currentyy}{\pgf@yy/1cm}%
\pgfmathsetmacro{\tikz@td@currentzx}{\pgf@zx/1cm}%
\pgfmathsetmacro{\tikz@td@currentzy}{\pgf@zy/1cm}%
\pgfmathsetmacro{\tikz@td@currentxz}{(\tikz@td@currentyx)*(\tikz@td@currentzy)-(\tikz@td@currentzx)*(\tikz@td@currentyy)}%
\pgfmathsetmacro{\tikz@td@currentyz}{(\tikz@td@currentzx)*(\tikz@td@currentxy)-(\tikz@td@currentxx)*(\tikz@td@currentzy)}%
\pgfmathsetmacro{\tikz@td@currentzz}{(\tikz@td@currentxx)*(\tikz@td@currentyy)-(\tikz@td@currentyx)*(\tikz@td@currentxy)}%
}
\tikzset{rotate about z axis/.code={%
\tikz@td@retrieve@current@basis
\pgfmathsetmacro{\newxx}{(\tikz@td@currentxx)*cos(#1)+(\tikz@td@currentxy)*sin(#1)}%
\pgfmathsetmacro{\newxy}{-1*(\tikz@td@currentxx)*sin(#1)+(\tikz@td@currentxy)*cos(#1)}%
\pgfmathsetmacro{\newyx}{(\tikz@td@currentyx)*cos(#1)+(\tikz@td@currentyy)*sin(#1)}%
\pgfmathsetmacro{\newyy}{-1*(\tikz@td@currentyx)*sin(#1)+(\tikz@td@currentyy)*cos(#1)}%
\tikzset{x={(\newxx cm,\newxy cm)},y={(\newyx cm,\newyy cm)},z={(\tikz@td@currentzx cm,\tikz@td@currentzy cm)}}%
},rotate about y axis/.code={%
\tikz@td@retrieve@current@basis
\pgfmathsetmacro{\newxx}{(\tikz@td@currentxx)*cos(#1)+(\tikz@td@currentxz)*sin(#1)}%
\pgfmathsetmacro{\newzx}{(\tikz@td@currentzx)*cos(#1)+(\tikz@td@currentzz)*sin(#1)}%
\tikzset{x={(\newxx cm,\tikz@td@currentxy cm)},
y={(\tikz@td@currentyx cm,\tikz@td@currentyy cm)},z={(\newzx cm,\newzy cm)}}%
},,rotate about x axis/.code={%
\tikz@td@retrieve@current@basis
\pgfmathsetmacro{\newyy}{(\tikz@td@currentyy)*cos(#1)+(\tikz@td@currentyz)*sin(#1)}%
\pgfmathsetmacro{\newzy}{(\tikz@td@currentzy)*cos(#1)+(\tikz@td@currentzz)*sin(#1)}%
\tikzset{x={(\tikz@td@currentxx cm,\tikz@td@currentxy cm)},
y={(\tikz@td@currentyx cm,\newyy cm)},z={(\tikz@td@currentzx cm,\newzy cm)}}%
}}
\makeatother
\begin{document}
\tdplotsetmaincoords{60}{130}
\begin{tikzpicture}[scale=2,tdplot_main_coords,>=Stealth]
\path (0,0,0) coordinate (O) (2,0,0) coordinate (O');
\begin{scope}[canvas is xy plane at z=0]
%Circle in xy plane at z=0
\path[fill=blue!40!white, draw=black] circle[radius=1cm];
\end{scope}
\begin{scope}[rotate about x axis=-20,canvas is xy plane at z=0,
shift={(O')}]
%Circle in transformed xy plane at z=0
\path[fill=red!40!white, draw=black] circle[radius=1cm];
\end{scope}
\draw[thick,->] (0,0,0) -- (5,0,0) node[pos=1.05]{$x$};
\draw[thick,->] (0,0,0) -- (0,5,0) node[pos=1.05]{$y$};
\draw[thick,->] (0,0,0) -- (0,0,5) node[pos=1.05]{$z$};
\end{tikzpicture}
\end{document}

1This statement refers to the orthographic transformations introduced by this library. It does not apply to the perspective view.
tikz-pgfand the question gets closed after a single vote as a duplicate. I will try to remdy that, and in the mean time if you don't think that Define different planes for drawings in TikZ sufficiently answers your question, please include a comment to that affect. – Peter Grill Jun 04 '20 at 20:41tikz-3dplotbut that's not very difficult to do, I think.) – Jun 04 '20 at 20:42shift={(O')}. – Jun 04 '20 at 21:16