Here are some examples how to format text.
Pages
Easiest way to create a new page is create a link to that page from another page. Then clicking to that link allows you create a new page - just enter your content and save.
Images / Files
This is similar to pages, just simply create a link to that file (please choose unique name that don't clash with other images / files), then click to that link and upload your file.
Math formulas
If you want to write a math formula, just simply write your formula in AMS-LaTeX format as
[math] formula [/math].
Here are some examples:
sqrt(x_1^2 + x_2^2)
[math]sqrt(x_1^2 + x_2^2)[/math]
\alpha\cdot\beta
[math]\alpha\cdot\beta[/math]
\lim_{x \to a} f(x)
[math]\lim_{x \to a} f(x)[/math]