When you add a request you can select the target directory where you want the files to end up (Root Folder). If you follow the Linuxserver.io setup, you should have created a bind volume called /media for where you want your media to end up for the use of Jellyfin which you can use.

A recent-ish Intel CPU. Even the mini pc’s with a n5000/n95/n100 class CPU will make light work of transcoding nearly everything into x265 using the igpu. The most recent gen will do AV1 decode/transcode as well.

When you say “no port forwarding”, do you mean you aren’t given a public routable IP address and you’re behind Carrier Grade NAT? Does your router get an IP address starting with 100 or 10?

If so just request a public IP, it might cost you extra but it’s worth it, that should open up the port forwarding option on your router.

I imagine you’re with a new altnet provider in the UK, is it LilaConnect by any chance?