I have my old phone and I can't get in because I forgot the Apple ID and the password
So my old phone I just found it and when I look at it its asking me for my Apple ID and password and I forgot it
Earlier iPhone models
You will need to find the Apple ID used and reset the password.
If you forgot your Apple ID - Apple Support
If you forgot your Apple ID password - Apple Support
The only other option would require your original purchase receipt from Apple or Authorized Apple Seller. No third party receipt would be accepted.