New Atahualpa user. Is this possible?

I am using Atahualpa for the first time. I am also fairy new to html/css. I am trying to make a website that looks something like this: http://caslynn.com/mockup.jpg

I have tried playing around in the theme options but am not figuring out how to do this. I am currently trying to make the main content area, navigation area, header, and footer area "float" on top of the background with space in between. Is there a more technical term for this? I was trying to search online and on this forum, but don't know what to call this "floating" look.

Thanks for any help!