Greetings, Berkeley1224.
It appears that you've changed the password for your Apple ID, and now, your Apple TV isn't accepting the change. I'm happy to help.
How to restart your Apple TV -- The first step is to restart your Apple TV. Once the restart has completed, test the issue.
What to do after you change your Apple ID or password -- This article lists the Apple services which use your Apple ID. If restarting your Apple TV didn't resolve the issue, try the old password to see if it's accepted. If it is, sign out with the old password and sign back in with the new one. Refer to this article to sign out of all Apple services and sign back in with the new information on all of your devices.
If your password still isn't being recognized, are you seeing any error messages?
Let me know how that goes.
Take care!