Hi and Welcome. My Name is ***** ***** I look forward to assisting you today with your question.
Apple ID would be the email address that you registered with Apple when you setup your iPhone. It would be your current email address or old email address (if any).
If you still don't remember it, then go to this website and fill the form --> https://iforgot.apple.com/appleid
This will find your Apple ID. If you don't remember the password ***** the ID you recovered, then you have to reset the password. You can reset it from here --> https://iforgot.apple.com/
Go to the above website. Use the "Email Authentication" method to reset the Apple ID. Apple will send the reset instructions to the recovery email you setup with your Apple ID. It would be your email registered with Apple, like Gmail, Yahoo etc. Open your email and you will see the email from Apple. Open it and follow the instructions to reset the password.
If that didn't work, then go to this site again --> https://iforgot.apple.com/
This time use the "Answer Security Questions" and answer the security questions there to reset your password ***** ID.
Please let me know if that didn't work, so I will continue to help you.