If your iPad says it's disabled, you'll need to connect it to iTunes or Finder to restore it. The exact steps will depend on ...
To reset or change your iPad's passcode, you can use the "Passcode" menu in your Settings app, or reset the entire device.
Unboxing a new iPhone shouldn't make you anxious about whether your information will safely transfer to the new phone. These are the ways to do it easily and safely.