Since you are using the Federal Free version, you likely made it to a certain step where it registered your account.
Your only other option (if you cannot work with what you have) would be to create a new TurboTax account to start fresh.
If you go to My Account then Save and Sign Out, you can choose to Create an account from the sign in screen.
You can have multiple usernames for the same e-mail address, but if you use your e-mail address as your username, you will need to create a username.
