You can attempt Google's account recovery procedure if you are unable to recall your Google account's username or password. call 1-888-303-0822 for help To confirm your identification, go to the Google Account Recovery page and follow the instructions. This might entail giving a phone number or email address linked to your account for recovery. If that works, you'll be able to go back into your Google account and change your password.
How do I recover my Google Account if I do not remember anything?