Latex Multiple Linebreaks

Line break accepts an optional argument in brackets, a vertical length:

line 1
\\[4in]
line 2

To make this more scalable with respect to font size, you can use other lengths, such as \\[3\baselineskip], or \\[3ex].

Insert some vertical space

blah blah blah \\
\vspace{1cm}

to scale to the font, use ex (the height of a lowercase "x") as the unit, and there are various predefined lengths related to the line spacing available, you might be particularly interested in baselineskip.

Do you want more space between paragraphs? Then you can change the parameter \parskip.

For example, try

\setlength{\parskip}{10pt plus 1pt minus 1pt}

This means that the space between paragraphs is usually 10pt, but can grow or shrink by up to 1pt. This means you give LaTeX the ability to change it up to one 1pt in order to achieve a better page layout. You can remove the plus and minus parts to make it always your specified length.

If you are trying to display source code, try the listings package or use verbatim. If you are trying to typeset pseudocode, try the algorithm package.