As outlined in the last step, you have an administration page. You simply want to click that link and it will take you to your Wordpress Login box.
Simply enter your login details that are provided to you within the "Details" link and you will gain access to the back-end of your site. Upon being logged in you will see the following screen. This is where you go to manage and edit your websites.
Alright! You are ready to move forward with content now. You have your site in place, you know how to manage it, you know how to access the administration area, now it is ready for some content! :)