4
You cannot position modules - you can, however, position blocks (which is called a module in Mambo terms - just to add to the confusion) which as I said is done in system admin -> blocks
Themes ARE colours and also overall positioning - which is not editable from XOOPS interface, but can be done on your local machine by opening up theme.html and style.css of the theme, you want to change.
If you don't know how to view your site, how on Earth managed you to go to admin menu and install modules?
I can't help you any more, if you ask questions as to how you play around or how to do "Everything"