Hi my name is ***** ***** to Just Answer. I am reviewing your question and will reply ASAP.
First you need to reset your Apple ID password. Go here to do that:
You can log into your Apple ID through your computer and remove the iPad from your devices.
Let me know if you have any questions. Please rate my advice using the star ratings.
In fact, after you reset your Apple ID password, you can try activating it without trying to remove it from your iCloud devices.
There's also a chance the Apple ID is different than the one in the hint on the activation screen, so if it is a different Apple ID you would need to sign in to all of your Apple ID iCloud accounts and check which one has the device listed.
Reply here if you have any problem resetting your Apple ID password.
Hi, have you been able to reset the Apple ID password?
Link to reset Apple ID password:
About activating the iPad:
Let me know if you have any questions, thanks!
Please take a moment to open the question page and rate my help using the star rating 3-5 stars. Much appreciated!