AWS

According to my Synology:

Where are you finding this data? It’s not Info Center -> Storage…

I use Portainer mainly to start / stop / restart containers without the mental load of using the command line. It works fine with Compose if you can get (or write) a yaml file for the container you’re interested in, or you can use it to pull from the repository and set everything up if you can’t. Portainer also gives you a nice, one-stop view of the current state of your containers. Basically, it can’t hurt to have it around.
Personally, my favorite Docker management GUI is the one that comes with Synology NASes. It’s much less clunky that Portainer and iirc a little more powerful. But of course it only runs in their hardware.

Masochism, paranoia.

Another vote for Debian, and I’ll suggest you go ahead and install Jellyfin directly rather than messing with Docker.
https://jellyfin.org/downloads/server
I’d been running JF under Docker on my NAS, but when I moved to a new server I decided to just install it directly and it hasn’t been any problem at all. You’ll get a notification when it needs to be updated and it’s just a few clicks to do so. You won’t have to fight with Docker to get hardware acceleration working - which isn’t to say it won’t be a PITA, but it’s one less layer of complication.