How to find multiple forgotton apple ids

The same way you would finding one forgotten one, just repeat it multiple times. ;-)

Typically an Apple ID is an email address you have used.

Click on this link to read about ways to find your Apple ID --> If you forgot your Apple ID email address or phone number - Apple Support

or go directly to this link --> https://iforgot.apple.com/password/verify/appleid#

If you still need help:

Contact Apple for help with Apple ID account security "This article provides country-specific Apple Support contact information for customers seeking help with their Apple ID password or other security-related issues."

Contact Apple for help with Apple ID account security - Apple Support