Do you see any specific errors?
If you can't update or restore your iPad - Apple Support
iOS update and restore errors - Apple Support
If your iPad is disabled/unavailable/locked-out, or you have forgotten your iPad passcode, you have no alternative other than to follow this process:
If you’ve forgotten the passcode on your iPad, or your iPad is disabled – Apple Support
You’ll need access to either a Windows PC (with iTunes for Windows installed) or a Mac (with iTunes or Finder - as appropriate for the installed version of MacOS).
Download and use iTunes for Windows – Apple Support
Update to the latest version of iTunes – Apple Support
Use of a PC or Mac is unavoidable. If you don’t have access to a suitable computer of your own, that of a helpful friend or family member will suffice. Alternatively, the technicians at the Genius Bar of your local Apple Store will be delighted to assist:
Genius Bar Reservation and Apple Support Options - Apple
You may also need your AppleID and associated password. If these have also been forgotten, they can be recovered here:
https://iforgot.apple.com
To recover your credentials, you’ll need access to one of the following:
- Your primary email address mailbox that corresponds with your AppleID
- Any of the secondary/recovery email addresses that should be configured for your AppleID account
- Any of the trusted telephone numbers (fixed line or Cellular/Mobile) that are associated with your AppleID
Unless you AppleID account has not been fully/correctly configured, or has been seriously neglected, recovery of the AppleID and password should not be difficult.
More information about recovery of your AppleID:
If you forgot your Apple ID - Apple Support
More information about recovery of your AppleID password:
If you forgot your Apple ID password - Apple Support
When you recover access to your 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