How do I use maps liiiike
theater_gmodmovietime_v4
gm_movie_theater
What addons do I need and are their any commands that I can access to play movies on it?
No. You can get an addon like PlayX to play Youtube movies on any map, Using a screen or a projector.
Those maps have a greenscreen, use chroma key in your movie editor to put something on it
Or an RT Screen, Spawn an RT camera and it might display on the screen.
Put them in garrysmod/garrysmod/maps