You should now be on the page to build your actual site. This is basically a page that shows you preview of what you have just specified you wanted your site to look like. If everything looks good to you, the next step is going to be clicking the"Build Website" button.
Upon clicking this button it will take 30 or so seconds to install and build your site for you. Once the engine is done churning together your site, you are going to get a pop-up that will give you all the "Details" for your site.
This gives you your website URL (where you can find it online) as well as your login details to the WP Adminstration area of your site (where you go to edit your site).
Your Website = The LIVE URL
Administration Page = Where you go to log into your admin
Username: The username you use for admin
Passowrd: The password you use to log in
Here is my example "iPhone 5 Cases" site if you want to check it out...