Example for a document with a numbered section title and three paragraphs:
\documentclass{article}
\begin{document}
\section{Introduction}
Lorem ipsum dolor sit amet, consectetuer
adipiscing elit. Ut purus elit, vestibulum ut, placerat ac,
adipiscing vitae, felis. Curabitur dictum gravida mauris. Nam arcu
libero, nonummy eget, consectetuer id, vulputate a, magna. Donec
vehicula augue eu neque. Pellentesque habitant morbi tristique
senectus et netus et malesuada fames ac turpis egestas. Mauris ut
leo. Cras viverra metus rhoncus sem. Nulla et lectus vestibulum urna
fringilla ultrices.
Phasellus eu tellus sit amet tortor gravida
placerat. Integer sapien est, iaculis in, pretium quis, viverra ac,
nunc. Praesent eget sem vel leo ultrices bibendum. Aenean faucibus.
Morbi dolor nulla, malesuada eu, pulvinar at, mollis ac, nulla.
Curabitur auctor semper nulla. Donec varius orci eget risus. Duis
nibh mi, congue eu, accumsan eleifend, sagittis quis, diam. Duis
eget orci sit amet orci dignissim rutrum.
Nam dui ligula, fringilla a, euismod sodales,
sollicitudin vel, wisi. Morbi auctor lorem non justo. Nam lacus
libero, pretium at, lobortis vitae, ultricies et, tellus. Donec
aliquet, tortor sed accumsan bibendum, erat ligula aliquet magna,
vitae ornare odio metus a mi. Morbi ac orci et nisl hendrerit
mollis. Suspendisse ut massa. Cras nec ante. Pellentesque a nulla.
Cum sociis natoque penatibus et magnis dis parturient montes,
nascetur ridiculus mus. Aliquam tincidunt urna. Nulla ullamcorper
vestibulum turpis. Pellentesque cursus luctus mauris.
\end{document}

Package indentfirst
If also the first paragraph right after the section title should be indented, then load package indentfirst:
\usepackage{indentfirst}

Package parskip
If you do not want the indentation of the first paragraph line, but vertical space between paragraphs instead, then load package parskip:
\usepackage{parskip}

Some document classes (e.g., KOMA-Script) configure this by options, thus that package parskip is not necessary and should not be used then.
\\in the text. So basically you are doing it wrong. Please explain know mare detail what is it you are trying and what you are expecting the output to be – daleif Sep 07 '15 at 06:09\bfseriesis a declaration, so we use{\bfseries foo}or\textbf{foo}. However, LaTeX can be overwhelming to a beginner. You're not the first to make mistakes like these and you certainly won't be the last. You should get yourself a good beginner's guide: http://tex.stackexchange.com/questions/11/what-are-good-learning-resources-for-a-latex-beginner. The number one rule, though, is do not hard code visual formatting features like1.or (generally) a hard line break or (in this case anyway) an explicit space – Au101 Sep 07 '15 at 16:49