What is the exact model Apple TV box? Legacy 2nd gen. (2010) or 4K 2nd gen. (2021)?
Identify your Apple TV model - Apple Support
Find your Apple TV model number - Apple Support
- Try the steps as mentioned in: If your Apple TV can't connect to Wi-Fi - Apple Support
- Try the ‘Other…’ option instead of selecting a listed discovered network. Especially if the password has been changed for a known (remembered) network name.
- For Apple TV (4th generation or earlier) (A1625 or earlier), verify that the router or access point isn’t set to use WPA3, as only device models from ~2018 or later support that. Instead use ‘WPA2/WPA3 Transitional’. Some users report that they had to set ‘WPA2’-only first.
… I wasn’t able to log into my Apple ID or test the connection.
To register the device or sign in for the iTunes Store on the legacy models, you may need to use a workaround method.
If you have a legacy Apple TV (2nd or 3rd generation) and two-factor authentication for your Apple Account, then you may be asked to type your password followed by the six-digit verification code directly into the password field. Additionally, there is a time limit, after which the code becomes invalid.
Try this: First enter the characters of your password (do not submit yet), then manually request a new verification code, then append that code to the password (no spaces or other separating characters), and then submit. That should help you get past the time limit.
Signing in for iCloud is no longer supported on the legacy models. See: thread 255664587.
My wife picked up a 2nd gen Apple TV box
For Apple devices that had prior users, it is best to start over from a reset state. If you are not greeted with the setup questions (first: Choose setup language), then please do a manual reset: Reset or restore your Apple TV to its factory settings - Apple Support