how to setup apple tv 4k

The remote is not working for my appletv 4k box. I am currently trying to get the remote to work on my phone but that has been no luck. The TV displays the apps but I cannot use the actual remote nor my phones. I got this at a garage sale and they stated they never "set it up" due to app purchases but--why am I having issues getting the remote on my phone to work/ setup. Do I need a new one? Trash it? Its not an apple tv just the box 4k-- I can see the apps but no remote.