There is no option ‘to forget ‘ network . Just says wi-Fi password not correct but won’t let me put a password ??!

What is your model Apple TV, and OS version? Identify your Apple TV model - Apple Support

What is your model phone, and OS version?

1. If your Apple TV can't connect to Wi-Fi - Apple Support
2. Try the ‘Other…’ option instead of selecting a listed discovered network. Especially if the password has been changed.
3. 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.

Also see: If Personal Hotspot is not working on your iPhone or iPad (Wi-Fi + Cellular) - Apple Support