Go to the sign in page of the product (for Google Accounts it is myaccount.google.com). Enter your Gmail username (everything that appears before '@gmail.com'). Enter your password.

You can also check if that username is saved in any of your browsers. If you have forgotten the password, and you have had recent access to the account and you are signed in to your Chrome Profile, you can visit https://passwords.google.com/ to see them.

Pulling your credit report and credit score is the most accurate and convenient way to find all of the accounts that have been reported in your name. Your credit report will display every open account in your name, from bank accounts to credit cards and more.