so, if i were to run umbrel on a mini computer in my home, and wanted to access say my nextcloud files or watch a movie via jellyfin not over tor. how exactly does that work? i am very used to start9 but umbrel not so much.

You have a couple options. You can use Tailscale which is a VPN which makes your devices able to connect remotely but act as though they are on the same local network. Or, if you own a domain, you can set up Nginx on your Umbrel after configuring a bit of port forwarding on your router. Trust me when I say this is far less complicated than it might sound.