Hi kaiocool:
I'm a newB too, so maybe I can help you. I also installed the WCMS though the Fantastico (don't ask me about sql). The simple steps to get the index.php working are very simple.
1. Go to the admin section (back end) and go to Admin> Page layout there you define the general spaces of your homepage, if you want so see something in the index.php try some colors in the spaces.
2. Next you will need a template that uses that page layout, the most importan thing is to put there the {content} tag in the main block, and images in the header or other blocks you want. Aslo consider the {NAV_TABLE_COLUMN} to get a menu.
3. Still you dont get nothing, now go to site structure and create the categories you want for your site (the sections).
4. Finally go to Admin > Article and creat an article under the index (website start) and that will be shown in your index.php
Remember that the version that the Fantastico installs is old, i'm going to try to update mine as well

because the newsletter management dosen't work right.
Hope this is helpful, if not ask Pappnase, he's the man around here and he's always there