I can recommend the dietpi OS; it is a minimal os that comes with a package manager for installing containers for things like radarr, sonarr, deluge, and jellyfin, which will allow you to download/watch movies(find on radarr, download with deluge, watch on jellyfin) and tv shows (find on sonarr, download with deluge, watch on jelyfin) in a fairly autonomous way. Its a bit of setup if you havent done it before it might not be for you but once its running its fairly seamless.