If you want your game to be first person, use first person. If you want it third person then use third person. Once you’ve got it running from a local player perspective you can then start to put avatars to represent other players into the world. You’ll want to use a different character class for them anyway so just make sure that the attached mesh is a full body rather than just some arms.
Remember, games can use a lot of tricks so just because you’re seeing the world in first person, it doesn’t mean that every other player has to see you or anything else in the world in the same way.