Ensure that you have properly erased the iPad in readiness for its new owner:
What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support
Having prepared the iPad for reuse by its new owner, you should be presented with the initial multi-lingual "hello" page:
Set up your iPhone or iPad - Apple Support
While the new owner of the iPad completes the initial setup, keep all other Apple devices away from the iPad that is being set-up. This will prevent QuickStart from detecting any devices in close proximity.
Assuming that the iPad was properly erased as described here, you should not have any opportunity to restore from a backup until the new owner's AppleID has been entered - and only then will any backups already associated with the new owner's AppleID (if any exist) be offered.
In summary, if performed correctly, you should have no opportunity to restore any of your own backups to the iPad.