activation lock

First you can try to recover your Apple ID email and password

If you forgot your Apple ID email address or phone number - Apple Support

If you forget your Apple ID or password – Apple Support (UK)

if this is not working and you're having valid proof of purchase you can start an Activation Lock support request.

If you forgot your Apple ID email address or phone number - Apple Support

If you forgot your Apple ID password - Apple Support

How to remove Activation Lock - Apple Support

If you cannot recover your Apple ID and Password using the links above then you cannot remove Activation Lock. Your only option then would be to take your original sales receipt to an Apple Store and ask for help in unlocking your phone. Otherwise you are out of luck. Sorry