Expanding upon the advice provided by Rudegar...
The following guidance is written from the perspective of the owner - however, close relatives usually have sufficient information, knowledge and access to recover access to the AppleID account. As you work through the following, you’ll get the idea...
First and foremost, before attempting to reset the iPad, you’ll need the AppleID and associated password. If these are unknown or have been forgotten, they can be recovered here:
https://iforgot.apple.com
To recover your credentials, you’ll need access to any one of the following:
- The primary email address mailbox that corresponds with the AppleID
- Any of the secondary/recovery email addresses that should be configured for the AppleID account
- Any of the trusted telephone numbers (fixed line or Cellular/Mobile) that are associated with the AppleID
Unless the AppleID account has not been fully/correctly configured, or has been seriously neglected, recovery of the AppleID and password should not be difficult. Close relatives contact information are also frequently included, in the configured Recovery methods, by savvy users.
More information about recovery of the AppleID:
https://support.apple.com/en-us/HT201354
More information about recovery of the AppleID password:
https://support.apple.com/en-us/HT201487
When you recover access to these credentials, you would be well advised to log-in to your AppleID account from a web browser - and verify/update any email addresses and trusted telephone numbers:
https://appleid.apple.com
If your iPad is or becomes disabled, or you have forgotten the iPad passcode, you’ll need to follow this process:
https://support.apple.com/en-gb/HT211078
You’ll need access to either a PC (with iTunes installed) or a Mac (with iTunes or Finder - as appropriate for the installed version of MacOS).
When you are ready to reset the iPad for reuse by a new owner, you may wish to prepare it properly:
What to do before you sell, give away or trade in your iPhone, iPad or iPod touch – Apple Support
I hope this additional information and guidance proves to be helpful in resolving any difficulties.
