Welcome.
Regarding dungeons ... well. One exists. Despite the misinformation most NPCs give. Probably brainwashed by the Octarchy. But it is not exactly packed with the most dangerous monsters. Neither are the few caves. There are other places with harder challenges.
Regarding raids ... I have no idea what that is, I never played WoW. PlaneShift is not as much conflict-oriented as other MMOs. It is rather cooperation-oriented, it uses to emphasize the "RPG". You are welcome to join as team and check the world out. You are welcome to create your own guild. But you should understand that PlaneShift has one main goal: Immersion. Play your characters as if they would live in this world and not know about anything outside this game.
If you are a guild of bandits, fine, play to be mean "In-character"; but "Out-of-character", as player in front of the keyboard, be nice to the other players, play fair.