The most likely kind of shooting
you will do should
have to draw and fire
at another person
in self defense
For a shooting to be considered justifiable the assailant would have to be quite close to you unless of course s/he was shooting at you from afar. Most self defense shootings occur in very close quarters where the luxury of an aimed shot is not really possible and in real up close and personal encounters like these, it is best to have a retention shooting grip which means the use of both hands having the handgun close to your body. Close enough to be able to point but not too close as to hamper the movement of the slide if you are using an automatic pistol.
So basically, once you have ascertained that there is in fact an up close threat to your life or limb and have decided to stop it with the use of lethal force, you draw, point and shoot.
If your shots made contact but did not yet stop the attack, you at least now hopefully have the extra time to aim and execute an incapacitating head shot. Read the mozambique drill.
May you never ever have to actually do this in real life, but should the need arise, it would be good to at least know how to do it.