Everything I hear about Nextcloud scares me away from messing with it.

I’m just running into this now. It also won’t let me log into the web interface. I’m glad I experimented with a second install before upgrading my primary pihole.

I tried Kopia but it was unstable and janky, so now it’s whenever I remember to manually run a bunch of rsync. I backup my desktop to cold storage on the first of the month, so I should get in the habit of backing up my server to the NAS then also.

Raspberry Pi 2 or 3 (can’t remember which) controlled through the TV with the remote. It’s running LibreElec (Kodi) with the Jellyfin plugin. Discoverability isn’t great through Kodi, but I can always use a computer or phone to find the media and cast if I need to.

As others have said, you don’t need to know how to code, but you do need to be comfortable editing structured documents, so knowing a little programming does help.
Unfortunately, Nextcloud and email are two of the most difficult things to self-host. This is by reputation, I haven’t tried myself. Email is supposed to be particularly difficult and the usual advice is to not bother.
Jellyfin is pretty straight-forward as long as you don’t have a weird hardware decoding setup and as long as you don’t want remote access. If you do want remote access you need to use third party tools to do it securely. If it’s just for your own use then Tailscale makes it really easy. If you want to share with non-technical users it gets messy.