IPad Air Setup

We recently got an Apple IPad Air that was delivered to our front door on Wednesday. We ordered an open-box one. When we tried to set up the IPad, it automatically told us to go to a website called support.apple.com/ipad/restore. We don’t understand why it starts out like that, and not in a different way. We tried to follow the directions where we plug in the cord to a computer, but we don’t know what computer to plug the cord into. Did someone use our Apple IPad before we got it, or are we doing something wrong?