There are several factions in the Settled Systems, and as players progress farther into Starfield's story, they'll become familiar with all of them. Gamers will come across the United Colonies Vanguard pretty early on in the game, as the faction's headquarters can be found right in New Atlantis, in the MAST District.
Starfield: Should You Join the Vanguard?
Gamers can join several factions in Starfield, so everything players need to know about becoming part of the United Colonies Vanguard.