Trail: Set Up Social Sign-On

Working on setting up Facebook - able to get the Facebook home page but I am not sure what to use for user and login information.  

1. Paste the URL into a browser.  THIS WORKED

1. If it works, you get the Facebook login page.
2. Log in to the Facebook page.  WHAT DO I USE TO LOGIN - THE INSTRUCTIONS DID NOT GIVE THIS STEP BUT SAID TO LOG IN. 
3. When prompted, authorize your app. You’re redirected to Salesforce, where you see the XML information that Facebook sent us.