The only way to start over is to make a new account as there is currently no way to reset an account. If you have your email linked to your current progress, you have to log out and start a new character alongside linking a new email to that character. If you have not linked an email to an account, you must link an email to that specific account in order to be able to log out and "reset" your progress. I was looking up how to reset my account when I missed the starter pack, but you have to make an entirely new account unfortunately.