FINALLY figured something out. putting my step-by-step here because im bad at computers and i dont want to forget it
make a folder in your files. this is where all the media you want on jellyfin will live from now on. make a bunch of subfolders in the main one (called the "root folder") for each type of media you want stored (e.g. music, movies, books, shows, whatever)
download tailscale to all the devices you want jellyfin on (do NOT skip this i promise you will need it later)
complete tailscale signup procedures
download jellyfin
complete the setup wizard on jellyfin (dont bother with adding folders unless you really want to, you can deal with it later)
give jellyfin permission to access your files
yayy youre done with setup on device A. now download jellyfin or an associated player (finamp, fintunes, symfonium, manet, etc. im using finamp so my music keeps playing even if my phone is off) on device B and add your server link
"elliott what even is my server link" "elliott its not working" shhhh. i know. it took me 3 days to figure this shit out, future Q. i am here to help you. go to tailscale and find the IP address of device A or whatever device you set jellyfin up on
take that IP address (it should only be FOUR BIG NUMBERS. FOUR. and it will look something like <123.45.678.90> or whatever combination device A decided its address is) (NOT THE 127 OR 10 NUMBERS. DO NOT USE THOSE.) and type it in using this format <http://> <ipaddress:8096>
"elliott what even is 8096" i dont know. i wish i did. im pretty sure it just tells device B that its allowed to join the server but that has a 99% chance of being wrong. its what makes jellyfin work on Not Device A so im choosing to leave it at that
good job, you are officially set up on device B. now you can go back to the folder stuff and do all that for the next one billion hours
add a media folder of your choosing. title it whatever your heart desires. copy the file address for the folder youre storing x media in so jellyfin knows exactly what youre trying to put on there.
repeat step 12 forever and congratulations! you now have a personal media server
other stuff
remember to scan your folders so it actually knows to read the files
i highly recommend getting a physical server (if you havent already) but im using my laptop rn and it seems ok so far. just remember to be mindful of how much storage youre using and you should be fine
