Go to a gun store. Buy a handgun . . . semi auto or revolver. Buy ammo. Buy a lot of ammo. Load gun and shoot. Repeat often. See goblin. Remember practice, aim and fire. Gun goes "bang". Goblin goes "auggh!" Repeat as necessary (until Goblin stops saying "auggh!"). That's all there is to it. Everything else -- type of gun, make and model of gun, ammunition, holster, etc. -- is purely secondary. .22 will kill you as dead as a .44 magnum. There is no magic.