You absolutely will have to get back into that account if you want those photos. Typically an Apple ID is an email address you have used. If you are currently using a mobile device that is logged into your account, go to Settings and tap your name at the top.
Look in Keychain, and in a browser's security settings if you use it to automatically sign into Apple when using a browser.
This support article describes ways to find your Apple ID --> If you forgot your Apple Account primary email address or phone number - Apple Support
or go directly to this link --> https://iforgot.apple.com/appleid
If you find you can’t sign in, you can request account recovery (read this support article: How to use account recovery when you can’t reset your Apple Account password - Apple Support ) to regain access to your account. Account recovery might take a few days or longer, depending on the specific account information you can provide to verify your identity. More detail in —> Activation Lockout Issues - Apple Community
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 support and service - Apple Support