I dont know

Break them down

Behind locked doors, there'll be buttons that unlock them (some buttons may be positioned a few feet from the door on a panel of some sort). Assuming that any significant updates to Garry's Mod didn't break anything, a red light indicates locked and pressing a button on the other side of the door is supposed to unlock that door and change the light to green.

So I checked out the map and the 2nd floor has a security door near the middle of the building that is unlocked by default which leads you to a room with a ladder. That ladder takes you up to the 3rd floor, into a corridor. This will take you toward the stairwell where there's more lock controls. There's a door after going up the stairs to the 3rd floor that's unlocked by default and on the other side of that door is another security door which is also unlocked by default.

As for the admin's room; it's only accessible by noclip. In the admin room, there's actually 3 buttons on the center screen. The top two (red and green) turns on/off the flashing alarm lights (no audible alarm sound).
The bottom button on the screen is a toggle switch that seems to only affect the large vertical moving door locking system. When set to "Unsecure", it'll prevent you from locking the door. When set to "Secure" it'll let you lock that door.