Hi James! It's great that you looked at other course offerings on Khan Academy, and that shouldn't have any affect on your access to the Praxis material. As long as you created your Khan Academy account with the email address you gave us when you signed up for the Praxis Core Prep Beta program, you should be able to access it here: www.khanacademy.org/prep/praxis-core/

Let me know if you run into any trouble, though, I'm happy to help you get started. :)