Sections and referencing

\documentclass{article}

\title{Sections and referencing}
\author{VK}
\date{\today}

\begin{document}

\maketitle
    
\section{A bigger section}

In Section \ref{introsection}
    
\section{My first section}\label{introsection}
This is my first section.

	\subsection{Another important thing}
    Hi
    \subsection{and another}
    Bye
    
\end{document}