First off:
I can't have shades on
Second:
My head's texture changes all the time.
So, how do I turn on shades?
And how can I prevent the
texture of the head to change all the time?

To put Shaders On Menu>Setup>Options

If u have an older version like 3.73 your head texture will always change download 3.8 here http://www.toribash.com/downloads.php

Jaysteels: read here to find more about shaders.

Also yes, the textures only work on Toribash version 3.8, so get that.