How to add indentation

Paragraph indention is controled by the parameter \parindent. In most document classes it is set to a positive value so you should see indentations. If this is not the case you can set this parameter in the document preamble to whatever value you wish, e.g.

\setlength\parindent{24pt}

Of course, a requirement is that you mark up your paragraphs: a paragraph ends by either a blank line or by the command \par. If you instead just used \\you have directed LaTeX to start a new line but not a new paragraph.

I think you need:

\indent Here comes your text

To forcibly insert a space that is the same length as an indentation you can use the following:

\hspace{\parindent}

This can be useful if you start a new section with a framed theorem, etc., and latex does not recognize it as a paragraph.