I set it up a while ago but if you search for guides I'm 100% sure you'll find them. I think jellyfin has their own guides. It gets a bit more complicated when you want to access it from outside your network. I use ddns (dynamic DNS) because my ISP doesn't give static addresses to residential customers. This allows me to have a hostname of xxxx.ddns.net. then I had to set up port forwarding on my router so that the jellyfin traffic is allowed through to my desktop that stores all my media. Internally on your LAN you'll need to have a static IP for your desktop too.