Personally i would recommend ubuntu Server and host as much you can over Docker and docker-compose files (selfhost is sooooo easy since docker!).

Ubuntu-Server is light weight and uses an common package manager which is widely used. Also the system is matured and frequently updated.

You can install portainer on the Server and manage all your containers/services through an easy UI.

Also you could install Watchtower on it, so all your docker-containers will be updated automaticly.

Edit: If you are just unsure about the Distro of choice, here is an pretty nice Website to search for distros of any kind: https://distrowatch.com/search-mobile.php?ostype=Linux&category=NAS&origin=All&basedon=All&notbasedon=None&desktop=All&architecture=All&package=All&rolling=All&isosize=All&netinstall=All&language=All&defaultinit=All&status=Active#simpleresults