National Guard Training Yard

Part of the quest “The Lost Patrol”

Has a Cooking station outside, and a separate Armory building. There is a bunker with mines in the entrance north of the main building. Inside, there are two remains with an ammo box beside them. That ammo box may contain 4 Fusion Cores.

National Recruitment Office

This main building has a couple of auto-turrets on the roof of its entrance. This is also where you'll find the corpse of Knight Astlin in one of the rooms there. There might be a Legendary Feral Ghoul Reaver. You can also pickup a Short Assault Rifle in the lower floor. There is also a green trunk in the corner of the room beside the desk that contains 3 Fusion Cores. You'll find 3 more Fusion Cores in another green trunk beside the Expert Terminal.

There is an Advanced Wall Safe in the corner of the room in the second floor with the collapsed floor. In the second floor office, you can get the National Guard Officer's Password from the desk. You can use that to open the security door which will Lead to the National Guard Barracks.

National Guard Barracks

As soon as you enter the barracks, you'll be ambushed by several ghouls. Make sure to have powerful close range weapons here like the shotgun or melee weapons. Continue upstairs. Check the room in the end of the corridor to the left to access the Armory Management Terminal. Use it to unlock the Armory door outside the premises. In that same room, you can find shotgun shells in the open safe. The room across has some recovery items like Radaway.

Be careful since there's a very powerful Glowing One in the next room. It's quite sturdy and you have to move around to avoid getting corned by it. Heck, even the minigun is no match for it. I was able to kill it when it got stuck in front of Dogmeat in the second floor. Other than that, you can either go back for this ghoul when you get stronger or if you have better equipment.

There's a U.S. Covert Operations Manual in the dining hall. The restroom has a Legendary Feral Ghoul Reaver. Killing it will drop a Kneecapper Laser Musket.

From the barracks, there's another door you can go through leading outside. Interact with the terminal and you'll be outside once again. The armory door should be opened after going through the Barracks area.

National Guard Armory

The room is filled with sensors. Triggering them will activate the turret on the wall and will release the protectron. A ghoul in the other room will be awakened as well. In the next room there's an armor and weapon benches, an ammo cache, and a Novice tool case.

In the locked room, there's a high-leveled Withered Feral Ghoul so don't open the door unless you're ready for it. Make sure to save before opening the storage area. After taking out the ghoul, the Power armor inside and all the components are all yours. Make sure you save first since after getting the power armor, a deadly Sentry Bot is waiting outside. You can use meds to outrun it and if you want to fight it, make sure to avoid open spaces.