Drupal Community Portal

Hi guys,
I'm very new to drupal and want to create a website. I implemented a page with a main navigation. It looks like this: http://14mb.de/u/advance/First.jpg
Now I want to make the site look like this: http://14mb.de/u/advance/Second.jpg
Can anybody give me a hint please where to start and how to move the blocks, respectively?
Thanks in advance,
enne