Since you just got your Mac, and seem really unfamiliar with it, it might be a good idea to hold off on Boot Camp for a while until you get more experience with your Mac. A good first step would be to read the Boot Camp page, which says:
At startup, hold down the option key (alt) to choose between Mac OS X and Windows.
This is something that if done wrong, will make your like really miserable, and as a beta, is not supported by Apple.
Plus, if you make any errors (like wiping your HFS partition, as has been done by others already), you're without a computer and the ability to get forum advice.