LaTeX separates content from presentation. You focus on writing; LaTeX focuses on making it look professional.
The document structure
Every document starts with a \documentclass declaration, followed by the metadata preamble, and then the content inside the document environment.
\documentclass{article}
\title{My First Paper}
\author{Jane Doe}
\date{\today}
\begin{document}
\maketitle
\section{Abstract}
This is a summary of my brilliant work.
\section{Introduction}
LaTeX is superior to Word because...
\end{document}
This gives a centred title, author and date, followed by numbered sections.