Originally posted by SoloQGames:

i guess you can't just start a server, you have to be online for the server to work or buy a dedicated one. seems janky

You CAN set one up on your own, the tools are provided to do so. Most folks don't have the knowledge, though. You only have to buy it if you don't want to bother hosting it yourself. Not through the game, but an actual separate dedicated server running on your own hardware and connected to the internet.

Yes, if you want to play with your friends, you have to either A: host it, or B: host it by renting a server, or C: host it by setting up your own server (not through the in game interface, that's option A).

Your lack of understanding does not jank make. The world has to be running for people to connect to it. That is universally applicable to any game like this that I can think of. Even Grounded's shared save system requires somebody to be hosting the game while it's played.

Your starting point: go to your library, and search 'valheim dedicated server'. That is what you want, for hosting a persistent world on your own without having to rent a server. I do not have the capacity to help you from that point though, it's too frustrating and I'm not getting paid.