Hello Rachael,
Thank you for the details of the issue you are experiencing when trying to sync your iPad. I recommend signing out of the iTunes & App Store setting, resetting your iPad, and trying to sync again.
Follow these steps to sign out of the iTunes & App Store:
Changing your Apple ID account
Tap Settings > iTunes & App Stores, then tap the Apple ID signed in.
Sign out of the current Apple ID account and then sign in with another account or create a new Apple ID.
iOS: Changing the signed-in iTunes Store Apple ID account
http://support.apple.com/kb/ht1311
Next reset your iPad:
Resetting your device
You can reset it by pressing and holding both the Sleep/Wake and Home buttons for at least ten seconds, until the Apple logo appears.
iOS: Turning off and on (restarting) and resetting
http://support.apple.com/kb/ht1430
Finally, try syncing your iPad again.
Thank you for using Apple Support Communities.
Best,
Sheila M.