You mixed here two things.
First: The part
\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib} % <===========================================
@BOOK{Human:1,
title = {{R}ocket {P}ropulsion {E}lements},
publisher = {John Wiley Sons},
author = Name J.~E.},
year = {2017},
edition = {4th},
}
@ARTICLE{Person:2,
author = {Jones, A.~B. and Smith, J.~M.},
title = {{A}rticle {T}itle},
journal = {{J}ournal {T}itle},
year = {2013},
volume = {13},
pages = {123-456},
number = {52},
month = {March},
publisher = {Publisher}
}
\end{filecontents}
is only used to build an compilable MWE including TeX code and bib file. Suppose you have the file mwe.tex then \jobname.bib is changed to mwe.bib to be accessable from the MWE.
Usually you have a file mybib.bib you can address to you code (if it is in the same directory) with \bibliography{mybib} Please see that the extention .bib is ommitted.
So in your case simply use
\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@BOOK{Human:1,
title = {{R}ocket {P}ropulsion {E}lements},
publisher = {John Wiley Sons},
author = Name J.~E.},
year = {2017},
edition = {4th},
}
@ARTICLE{Person:2,
author = {Jones, A.~B. and Smith, J.~M.},
title = {{A}rticle {T}itle},
journal = {{J}ournal {T}itle},
year = {2013},
volume = {13},
pages = {123-456},
number = {52},
month = {March},
publisher = {Publisher}
}
\end{filecontents}
\documentclass[11pt,a4paper,oneside]{article}
\usepackage{natbib}
\usepackage{url}
\usepackage[utf8x]{inputenc}
\usepackage{siunitx}
\usepackage{indentfirst}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{arrows}
\usetikzlibrary{patterns}
\usepackage{caption}
\usepackage{pgfplots}
\usepackage{listings}
\usepackage{color}
\usepackage{graphicx}
\graphicspath{{images/}}
\usepackage{parskip}
\usepackage{cite}
\usepackage{fancyhdr}
\usepackage{vmargin}
\setmarginsrb{3 cm}{2.5 cm}{3 cm}{2.5 cm}{1 cm}{1.5 cm}{1 cm}{1.5 cm}
\usepackage[colorlinks]{hyperref} % <===============================================
\title{Life is too short to learn LaTeX} % Title
\author{Rageful} % Author
\date{01.01.2019} % Date
\makeatletter
\let\thetitle\@title
\let\theauthor\@author
\let\thedate\@date
\makeatother
\pagestyle{fancy}
\fancyhf{}
\rhead{\theauthor}
\lhead{\thetitle}
\cfoot{\thepage}
\renewcommand{\refname}{Referance}
\begin{document}
\begin{titlepage}
\centering
\vspace*{0.5 cm}
\includegraphics[scale = 0.08]{latex.png}\\[1.0 cm]
{\centering \textsc{\LARGE \ \ \ \ \ \ \ \ \ LATEX} \newline\newline \textsc{\LARGE PROJECT}\\[2.0 cm]}
\textsc{\Large 17.01.2019}\\[0.5 cm]
\rule{\linewidth}{0.2 mm} \\[0.4 cm]
{ \huge \bfseries \thetitle}\\
\rule{\linewidth}{0.2 mm} \\[3.5 cm]
\begin{minipage}{0.5\textwidth}
\begin{flushleft} \large
\emph{Person A}\\
\end{flushleft}
\end{minipage}~
\begin{minipage}{0.4\textwidth}
\begin{flushright} \large
\emph{Person B :} \\
\end{flushright}
\end{minipage}\\[2 cm]
\end{titlepage}
\section{Preface}
Why is LaTeX too hard? \cite{NAME:1}
\newpage
\bibliographystyle{unsrt}
\bibliography{\jobname} % bibliography prints here
\end{document}
to show your issue with an MWE.
SECOND: in real simply use
file mybib.bib
@BOOK{Human:1,
title = {{R}ocket {P}ropulsion {E}lements},
publisher = {John Wiley Sons},
author = Name J.~E.},
year = {2017},
edition = {4th},
}
@ARTICLE{Person:2,
author = {Jones, A.~B. and Smith, J.~M.},
title = {{A}rticle {T}itle},
journal = {{J}ournal {T}itle},
year = {2013},
volume = {13},
pages = {123-456},
number = {52},
month = {March},
publisher = {Publisher}
}
and the productive tex code, for example test.tex (see command \bibliography{mybib} at the end):
\documentclass[11pt,a4paper,oneside]{article}
\usepackage{natbib}
\usepackage{url}
\usepackage[utf8x]{inputenc}
\usepackage{siunitx}
\usepackage{indentfirst}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{arrows}
\usetikzlibrary{patterns}
\usepackage{caption}
\usepackage{pgfplots}
\usepackage{listings}
\usepackage{color}
\usepackage{graphicx}
\graphicspath{{images/}}
\usepackage{parskip}
\usepackage{cite}
\usepackage{fancyhdr}
\usepackage{vmargin}
\setmarginsrb{3 cm}{2.5 cm}{3 cm}{2.5 cm}{1 cm}{1.5 cm}{1 cm}{1.5 cm}
\usepackage[colorlinks]{hyperref} % <===============================================
\title{Life is too short to learn LaTeX} % Title
\author{Rageful} % Author
\date{01.01.2019} % Date
\makeatletter
\let\thetitle\@title
\let\theauthor\@author
\let\thedate\@date
\makeatother
\pagestyle{fancy}
\fancyhf{}
\rhead{\theauthor}
\lhead{\thetitle}
\cfoot{\thepage}
\renewcommand{\refname}{Referance}
\begin{document}
\begin{titlepage}
\centering
\vspace*{0.5 cm}
\includegraphics[scale = 0.08]{latex.png}\\[1.0 cm]
{\centering \textsc{\LARGE \ \ \ \ \ \ \ \ \ LATEX} \newline\newline \textsc{\LARGE PROJECT}\\[2.0 cm]}
\textsc{\Large 17.01.2019}\\[0.5 cm]
\rule{\linewidth}{0.2 mm} \\[0.4 cm]
{ \huge \bfseries \thetitle}\\
\rule{\linewidth}{0.2 mm} \\[3.5 cm]
\begin{minipage}{0.5\textwidth}
\begin{flushleft} \large
\emph{Person A}\\
\end{flushleft}
\end{minipage}~
\begin{minipage}{0.4\textwidth}
\begin{flushright} \large
\emph{Person B :} \\
\end{flushright}
\end{minipage}\\[2 cm]
\end{titlepage}
\section{Preface}
Why is LaTeX too hard? \cite{NAME:1}
\newpage
\bibliographystyle{unsrt}
\bibliography{mybib} % bibliography prints here <====================
\end{document}
Please see that I changed the order of calling hyperref: in your case is should be called last and do not call packages twice (I deleted the second call of hyperref in the code above) ...
UPDATE:
Now let us have a look on your given code. There are some issues too:
You called package cite causing the error you mentioned. Please read the documentation of cite with typing texdoc cite on your terminal/console. If you want to use package cite, you need to delete the call of natbib (you can not use both together) and use \bibliographystyle{unsrt}.
If you want to use natbib (please read documentation with texdoc natbib on your console/terminal) you need to delete the call of cite and to change the used bibliography style to \bibliographystyle{unsrtnat}. To get numbered bib entries add option numbers to natbib: \usepackage[numbers]{natbib}. For the following MWE I choosed this variant ...
In your bib entry Human:1 is a { missing for author:
@BOOK{Human:1,
title = {{R}ocket {P}ropulsion {E}lements},
publisher = {John Wiley Sons},
author = {Name J.~E.},
year = {2017},
edition = {4th},
}
In your bib file is no bib entry NAME:1 you call in your tex code. I changed it to Human:1.
Now please see the following compilable code
\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@BOOK{Human:1,
title = {{R}ocket {P}ropulsion {E}lements},
publisher = {John Wiley Sons},
author = {Name J.~E.},
year = {2017},
edition = {4th},
}
@ARTICLE{Person:2,
author = {Jones, A.~B. and Smith, J.~M.},
title = {{A}rticle {T}itle},
journal = {{J}ournal {T}itle},
year = {2013},
volume = {13},
pages = {123--456},
number = {52},
month = {March},
publisher = {Publisher},
}
\end{filecontents}
\documentclass[11pt,a4paper]{article}
\usepackage[numbers]{natbib} % <===================================
\usepackage{url}
\usepackage[utf8x]{inputenc}
\usepackage{siunitx}
\usepackage{indentfirst}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{arrows}
\usetikzlibrary{patterns}
\usepackage{caption}
%\usepackage{pgfplots} % <========================= not needed for issue
\usepackage{listings}
\usepackage{color}
\usepackage{graphicx}
\graphicspath{{images/}}
\usepackage{parskip}
\usepackage{fancyhdr}
\usepackage{vmargin}
\setmarginsrb{3 cm}{2.5 cm}{3 cm}{2.5 cm}{1 cm}{1.5 cm}{1 cm}{1.5 cm}
\usepackage[colorlinks]{hyperref} % <===============================================
\title{Life is too short to learn LaTeX} % Title
\author{Rageful} % Author
\date{01.01.2019} % Date
\makeatletter
\let\thetitle\@title
\let\theauthor\@author
\let\thedate\@date
\makeatother
\pagestyle{fancy}
\fancyhf{}
\rhead{\theauthor}
\lhead{\thetitle}
\cfoot{\thepage}
\renewcommand{\refname}{Referance}
\begin{document}
\begin{titlepage}
\centering
\vspace*{0.5 cm}
\includegraphics[scale = 0.08]{example-image}\\[1.0 cm]
{\centering \textsc{\LARGE \ \ \ \ \ \ \ \ \ LATEX} \newline\newline \textsc{\LARGE PROJECT}\\[2.0 cm]}
\textsc{\Large 17.01.2019}\\[0.5 cm]
\rule{\linewidth}{0.2 mm} \\[0.4 cm]
{ \huge \bfseries \thetitle}\\
\rule{\linewidth}{0.2 mm} \\[3.5 cm]
\begin{minipage}{0.5\textwidth}
\begin{flushleft} \large
\emph{Person A}\\
\end{flushleft}
\end{minipage}~
\begin{minipage}{0.4\textwidth}
\begin{flushright} \large
\emph{Person B :} \\
\end{flushright}
\end{minipage}\\[2 cm]
\end{titlepage}
\section{Preface}
Why is LaTeX too hard? \cite{Human:1}
\newpage
\bibliographystyle{unsrtnat} % <==================================
\bibliography{\jobname} % bibliography prints here
\end{document}
and the resulting pdf:

At last a remark: your used \ \ \ \ \ \ \ \ \ to build your title page is wrong. Better use \vspace{3cm} and change the used value for your needs ...
\begin{filecontents}{\water.bib}correct? Should it be\begin{filecontents}{water.bib}? – Mico Jan 03 '19 at 23:37\watertowater, (b) not load thenatbibpackage (since it's a mistake to load bothnatbibandcite), (c) in the entryHuman:1, changeauthor = Name J.~E.}toauthor = {Name J.~E.}(can you spot the missing{symbol?), and (d) used\citecommands to cite eitherHuman:1orPerson:2. Your code currently features\cite{NAME:1}, but you do not provide an entry with keyNAME:1... – Mico Jan 04 '19 at 00:22