I have a couple of links for you regarding FaceTime and Messages that may help you resolve this issue:
How do I enable iMessage for use with Messages?
You can enable iMessage in multiple ways, depending on your device:
iPhone: Turn Messages on in Settings > Messages. Messages will begin registration with your carrier-assigned cellular telephone number. Sign in with your Apple ID to also use your e-mail with Messages.
iPad and iPod touch: Navigate to Settings > Messages. Sign in with your Apple ID.
Follow these steps if you are experiencing difficulty activating your telephone number or Apple ID with iMessage.
If these do not address your issue, would you mind providing a bit more information about what you are trying to accomplish, please. Thanks for coming to the Apple Support Communities!