Hello emma20x,
It sounds like you have a passcode on your iPad that will not allow you to boot to your Home Screen or you needing to reset your Apple ID password. If you are referring to a passcode, use this article to reset that:
iOS: Forgotten passcode or device disabled after entering wrong passcode
http://support.apple.com/kb/ht1212
If you need to reset your Apple ID password, use this article:
Apple ID: Changing your password
http://support.apple.com/kb/ht5624
Thank you for using Apple Support Communities.
Take care,
Sterling