From Destinypedia, the Destiny wiki
The Khvostov 7G-02 is an ancient basic Auto Rifle found in The Breach in the Cosmodrome. It is the first weapon a Guardian acquires, during the very first mission/tutorial A Guardian Rises.  Its only perk is Kinetic damage. It reprises its role as the first weapon acquired for new Guardians in the Shadowkeep expansion for Destiny 2.
List of appearances