Don’t know what to do now.

I’m a total newbie to this stuff and have just struggled my way through the install. However, I don’t know what to do now. I had previously signed up for a WordPress account on wordpress.com, but I don’t know how to have it recognize that I’m running WordPress on my server. Does this make any sense? Essentially, I installed it, it gave me admin user and pass, but I don’t know what to do with that. How do I start my blog?