The Beeline is definitely powerful enough to run a hypervisor, so I would do that if I were you. Proxmox is a very good product and easy enough to use. Personally I use Harvester (with Rancher) but that might be a bit daunting if you've not used Kubernetes before.
I would recommend running Proxmox as your OS, spin up a few Debian virtual machines and run your services (Nextcloud, plex/jellyfin, ...) with Docker containers. I would personally use Podman, as I think it's the simpler one to use, but there might be more documentation online for Docker, I'm not sure. But do definitely use containers! You'll thank yourself in 6 months.