Hi Jason,
Welcome to Apple Support Communities.
If I understand correctly, your iPad is able to connect to iTunes and iCloud but it isn't able to connect to Game Center. Try taking a look at the at the article linked below and running through the general troubleshooting tips that it provides.
Using Game Center on your Mac or iOS device - Apple Support
If you can't sign in to Game Center or stay connected, follow these steps:
- Make sure that you're connected to the Internet.
- If you can't create an account or sign in to Game Center from within a game, try to create an account or sign in using the Game Center app.
- Sign out of Game Center, then sign back in. If you can't sign in to Game Center with an Apple ID, reset your password or use another email address. To manage your Apple ID, go to My Apple ID.
- If you're using a Wi-Fi connection, make sure that your Wi-Fi router is configured for Game Center.
- If you can't sign in on a Mac, continue with the steps to resolve sign in issues.
If you have an issue with a Game Center game, follow these steps:
- Make sure that you have the latest version of the game. To check for updates, go to App Store > Updates.
- Test your connection using a different game. If you can't connect with a specific friend or player in multiple games, they might need to check their Wi-Fi connection and router settings.
- On iOS, try opening the game from the Home screen, rather than from within Game Center.
- If you can't solve the issue, follow the steps in the next section to report the problem to the developer.
Ciao.