Hello, my name is***** hope to help you with this problem.
On the Apple TV, on the main menu, do you see the Settings Gear?
Enter the Settings menu, then click General ,then Network. Click Test Network. If presented with the option to enter your iTunes Store Username and Password, do so. If not, answer the questions to the best of your knowledge and let the test continue.Once the test is finished, provided the result is positive, exit to the main menu and attempt to use the AppleTV with your username and password. If it still isn't working, return to the Settings menu, click iTunes Store, then Sign-In. Attempt to enter your username and password *****Try to access the iTunes Store again. If the password ***** ***** incorrect, reset your password *****. After, attempt the steps above again.
Hello again, this ticket is still open. If you require further assistance, I am here to help!