I tried for awhile to make osmc work on an raspi4 for media playing and it was always just… not quite there.
I ended up going with a Ebay mini pc with Plex on it and stream to my TV with a Roku stick. Just worked so much better without much effort on my part.
Seconding pop os for a solid starter Linux distro.
Been daily driving it for about 3 years now i think.