You know what? I read an article about this exact same problem!
So here is it: [https://www.joyoshare.com/iphone-repair/ipad-is-disabled-connect-to-itunes.html|iPad is disabled connect to iPad]
Basically, you hook up your iPad with your mac, and you will see a notification telling you to restore the iPad.
If not, the easiest solution is to use Joyoshare [https://www.joyoshare.com/ultfix-for-win/|iPad System Recovery] to restore the iPad without data loss.