You are supposed to bring your own friends or family. Or you supposed to use the looking for group forums here or on the official Valheim Discord channel. Or you can ask around on the Valheim Subreddit. Or you can run your own server and advertise it in one of these places. Or you can just run the single player and check "start server" and your friends can join , this option does not require a dedicated server , but friends can only join you while you are playing.

And unless they changed it I do not believe you are forced to use a password. I think you can leave it blank.

But if you are looking to jump into random servers and grief people then it will be difficult.