Most servers are private, either hosted or dedicated. If you have friends you can invite them to your world or vise versa.

the only downside to multiplayer with people you dont know is that it requires the server Host to break immersion to perform the job of a server admin which is what ruined server hosting for me in other games like Minecraft and Terraria. the last thing i want to do is be reminded im playing a game because some jerk logs in and uses cheats to give themselves GOD MODE which also grants you GOD MODE when you get near them... the security for multiplayer is very rudimentary right now relying exclusively on your own capability as a host to provide a safe experience for your guests. though at Nexus Mods there are some creators which have added functions similar to the famous buckit plugins for Minecraft making it more difficult for people to cheat or abuse mechanics...these are still very rudimentary and require some "learning" in the modding scene to fully understand how to implement. none of those features are directly supported by Iron Gate so any guides on how they work may become outdated which many have due to a lack of continued interests by mod authors to maintain their stuff due to a lack of trust in Iron Gate as a dev.

Simple solution. only play with friends you know... but when your friends cheat, and it annoys the living frick out of you... decide if you value your friends or this abandonware game more before you chastise them over it.

Go over to the Looking for Group sub menu to the right, there people post if they are looking for others to play on their online server. Just leave message in the posting or there are instructions on how to contact someone.

My advise would be look for server that is starting new world so all will be same if they are starting new characters.
Hope this helps

Like @TheFormalGoat wrote most servers are private these days. Griefers make many people cautious so better safe than sorry.

You will occasionally see open servers or see notes in the forum about someone starting a new multiplayer world and asking if anyone is interested in joining.

But if you can get a few 'whitelisted' people you can have a great time multiplayer wise.

as the users above say the game do have multiplayer/co-up.
And reason there are not so many opens servers are that people can just jump into a game and take your best stuff and then jump back to their own game with your stuff.
I dont know if the server admin can prevent this somehow but i hope so.
Also some people just come to damage your buildings and ruin your game.
Well basicly you dont want to play with everyone even if you could.
But game do have multiplayer and it make fighting the boss more easy if you work together with friends.

it's not misleading, you didn't just look properly.
it's in the game menu, and actually it's mainly a Coop game.
but single player is an option as well.

Most servers are private, either hosted or dedicated. If you have friends you can invite them to your world or vise versa.

after character creation, at the worlds window is where MP is (but i dont use it :-) ) GL