After exploring the site (and talking to user service employees many, many times), I decided to check out my profile. You only need basic information to sign up, and once you have an account, it is effortless to edit your account if you must change it. All you need to do is go to your profile and hit the "Edit" button at the top of your Profile Information.
Also, you should know your information if you decide to call user service; they typically ask for it at the beginning of a call.
After ensuring that your account information is correct, you can begin exploring your Pro Xtra account.