You will get the Pistol and the Praetor Suit as you go through the introductory parts of this level, as well as get your first taste of Glory Kills before getting your hands on the Combat Shotgun.
You awaken from your slumber to find yourself surrounded by the living dead, and after taking them out and reclaiming your battlesuit, you learn that a demonic invasion is underway on Mars, and that the UAC facility has been overrun by Hellspawn.
The mission that has you going through this level is called, 'Rip and Tear.' The UAC is the first level of Doom (2016), and the player's first introduction to the UAC, Samuel Hayden, Olivia Pierce, the demons, and the Doom Slayer.
Rip and tear, until it is done.' ― Novik upon starting the level