If you forget your Apple ID or password
Your Apple ID is your user name for the App Store, iTunes Store, Apple Books, iCloud and other Apple services. It’s also used to manage your Apple ID settings on your Mac.
If you forget your Apple ID or password, you can reset them using Apple ID settings on your Mac.
On your Mac, choose Apple menu
Click “Forgot Apple ID or password?”, then do one of the following:
If you forgot your Apple ID: Click Forgot your Apple ID?, then follow the onscreen instructions.
If you know your Apple ID: Enter your Apple ID, click Continue, then follow the onscreen instructions.
For more information, see the Apple Support articles If you forgot your Apple ID email address or phone number or If you forgot your Apple ID password.
You can also go to the Apple ID account website to help you find your Apple ID.
Go to the Apple ID account website, click Sign In, click “Forgot Apple ID or password?”, then follow the onscreen instructions.