Restoring my Iphone 7 but no longer have active phone number

You may have a problem. When you set up 2 factor authentication you were encouraged to add alternate ways to get authorization codes. If you did you will have to use one of those. If you did not you will have yo use Apple’s account recovery service. See—>Two-factor authentication for Apple ID - Apple Support

You should have no problem restoring a phone that doesn't have cellular service as long as it still has a SIM in it and you have a Wi-Fi connection. It can be the original SIM even if deactivated.