Basically you need to do it for each. The numbering system is based on counters, and each number has its own counter. Resetting all counters would include things you don't want to reset, like page numbers. As said in the comments, different document classes treat the counters different. In book
for example, things like section
, subsection
, equation
, table
and figure
are automatically reset at each chapters start. But for example theorem
and lemma
, and other things you define by your self, you need define it such that it the counter reset at chapter start. For example:
\documentclass{book}
\usepackage{graphicx}
\newtheorem{theorem}{Theorem}[chapter] %%% Reset theorem counter at chapter start
\begin{document}
\chapter{First chapter}
\section{First section}
\begin{theorem}
As can be see in Figure~\ref{fig:Test1}...
\end{theorem}
\begin{figure}[htb]
\centering
\includegraphics[width=0.3\linewidth]{example-image-a}
\caption{Test figure.}
\label{fig:Test1}
\end{figure}
\section{Second section}
\begin{theorem}
Test
\end{theorem}
\chapter{Second chapter}
\section{First section}
\begin{theorem}
Euler's identity
\begin{equation}
e^{i\pi}+1=0
\end{equation}
\end{theorem}
\begin{figure}[htb]
\centering
\includegraphics[width=0.3\linewidth]{example-image-a}
\caption{Test figure.}
\label{fig:Test2}
\end{figure}
\section{Second section}
\begin{theorem}
Test
\end{theorem}
\end{document}
First chapter:

Second chapter:

book
class. If you are using something else or have defined counters on your own, plase provide a full minimal working example which reproduces the issue.