NO. If you don't already have one, you DON'T need to go get a gun.
What you really really need to do?
-de-escalation training
-First aid training
-Gunshot wound first aid specifically
-unarmed self defense, pick any
-gun disarmament training
-gun use training with multiple types of firearm
But that sounds hard and unsexy and responsible so let's just talk about possible shootout scenarios that will never happen/s