It happens. First, did you get any email on any of your addresses (receipts, other new customer emails...)? Otherwise, you can contact 24/7 Support and validate by payment method (credit card) for assistance.
You can also send your customer number and do a password reset from our homepage (see where those emails end up). Finally, if there is no help in recalling or you think there might have been a typo in what was entered, you can update the email on an account at www.changeupdate.com with the required ID.
I hope that helps,
Thomas D. - GoDaddy | Community Moderator 24/7 support available at x.co/247support