My first “homelab” was an old computer running Debian with a Minecraft server, Jellyfin, Navidrome, and a few other random things for fun.
More recently, I bought a slightly newer second-hand Mini-ITX system. It’s running TrueNAS SCALE with Nextcloud, Jellyfin, Immich, and some networking services.
The system came with a nice Fractal Ridge case, but I’m designing a custom 3D printed rack for even greater space efficiency.