Create a master or main page
You may need to do some research into the way the drupal system works. Here is the documentation page for how to theme drupal. http://drupal.org/documentation/theme 

If you are looking to create you own theme. For a beginner, it may be easier to start with a theme framework to mold it into what you want. Here are 3 of some of the more popular frameworks; Zen, Fusion, and Adaptive Theme.

P.S. - You may want to consider doing some basic google research prior to asking questions on here without more supportive information.