i forgot my password for my apple tv

apple tv does not have a password at all

appletv require passwords for

1. if connected by wifi to a encrypted wifi network it require the wifi password

2. if one use services which require the user to use the appleID it will require the appleID password

if you forgot the appleID password then

https://iforgot.apple.com/iForgot/iForgot.html

found with this google

https://www.google.dk/search?client=opera&q=reset+apple+id&sourceid=opera&ie=utf -8&oe=utf-8&channel=suggest