If you've forgotten your username or password (or both), you can reset them in Control Center. If you've forgotten both your username and password, set your username first, then your password. You'll need to know the answers to the security questions you created when you registered as a Control Center user and you'll need to be able to access the email address associated with your Control Center user profile.
If you've forgotten your password and have tried to log in several times, your user profile may be locked. If your user profile is locked, you can still reset your password, but you must wait thirty minutes for your user profile to be unlocked before trying to log in again.