Q: apple ID cannot be used to unlock this iPad.

recently just downloaded iOS 9.3 on my iPad 2, and i put my apple ID and password, and it says it cannot be used to unlock this iPad, I’m not sure what else I’m supposed to do. I’ve connected it to my laptop, and went on iTunes, it said the same thing. But when i go on iCloud.com, my apple ID works, but my iPad is not shown.