Apple TV App Not Working on MacBook Air

My TV app is opening up but only showing content which I've downloaded. I've tried shutting down the computer and restarting, quiting the app several times. My internet is working fine. I have a Macbook Pro as well and that is working just fine. Ive tried to update to the latest software and it says Unable to Check for Updates. It seems to think it's not connected to the internet but it is just like my other computer which is working fine. Any ideas on what else I could do?