Starfield: How to Join the UC Vanguard
As with any role-playing game developed by Bethesda Game Studios, Starfield also features a multitude of factions. Just like in any BGS RPG, a signifi...

As with any role-playing game developed by Bethesda Game Studios, Starfield also features a multitude of factions. Just like in any BGS RPG, a significant portion of the game's extensive storytelling unfolds within these factions. Hence, you may want to give it a shot, even if you're not particularly interested in the UC Vanguard - and in our opinion, it's a rather captivating questline!
In comparison to some other factions in Starfield, joining the UC Vanguard is rather straightforward, but like with all of them, you still need to prove your worth. Here's precisely how you can accomplish that.
Where To Find Tuala
It's entirely painless to locate Commander Tuala, who will assign you the mission to unlock the UC Vanguard. In fact, you will naturally encounter him during a very early story mission, and he will even present you with the best-selling pitch for recruiting the Vanguard, much to Sarah's amused annoyance.
To handle things in the most efficient manner, simply wait for Sarah to join you after you introduce yourself at the lodge, which is pretty much the first significant task upon arriving in New Atlantis. Before your departure, you will have a chat with both Sergeant Yumi (who will unlock a series of non-faction-related quests if you engage in further conversation) and Tuala.
Regardless of your response at this point, you won't be prevented from joining later. How much later? In our experience, we were able to turn around right after the conversation with the story and speak with Tuala again, informing him of our desire to join and proceeding from there. If, for any reason, the option isn't immediately available to you, leave the zone and return to him or wait until after your mandatory mission with Sarah.
Entering The Simulation
You don't have to go far to prove to Tuala that you have the potential to be a member of the Vanguard. He will send you to the designated floor, as indicated by your mission objective marker. Although it's not necessary to engage with the terminals in the UC Historical Exhibition as you make your way to the simulator, we strongly recommend taking the time to interact with each terminal.
Not only does it help establish a significant amount of important background information, not just for Starfield in general, but also for the Vanguard questline specifically, but Tuala's reception upon your return will be warmer if you do so, which apparently affects the quest's reward.
Our main task is to win three consecutive rounds in the space combat simulator, to which the mission objective marker will guide you. The first two rounds are quite straightforward, but the third one can be quite challenging if you're not familiar with this type of gameplay yet.
Win Three Rounds... Maybe More
If you don't join much later in the game, you probably won't have access to advanced mechanics like target locking. Just do your best to maneuver past enemy ships, stay outside of their firing range, and press all three weapon buttons to quickly and effectively inflict damage upon them.
You can continue to progress in ranks within the simulator before reporting, but be aware that things will become very challenging. If you found the third and final required stage easy enough, you will likely find the fourth one relatively straightforward as well. However, at this point, make sure to interact with the terminal again to access modifiers and add allies, enhance shields, and/or upgrade your weapons. In fact, it is highly recommended that you do so once, as it improves Tuala's evaluation of your performance.
If you get stuck, don't get discouraged - we suspect most players will, and that's perfectly okay. It's a bloodbath in there. Just proceed and report your results.
Now, speak with the supervisor who is standing outside, and then go downstairs to talk to Tuala again. Follow him outside, take the oath, and then you're good to go!