Apart from fixing the grammar in this post, you really should think about your question(s) a little bit more and provide more context. For example, do you have any type of formal firearms training? Do you plan or are you already carrying your handgun in public for the purpose of self defense? Do you have the necessary gear, such as a good holster and belt? If your state requires it, do you have a carry permit? Do you carry a spare magazine? If not, do you know why you should?
Shooting groups at the range is target shooting and only very little translates into self defense applications. Target shooting is good for practicing sight picture/alignment and trigger control, essential components of all shooting sports. However, there is much more to using a handgun in self defense. Can an untrained person successfully defend himself/herself? Sure. However, the success rate drastically increases with some training. Get some training.
Many self defensive shootings are at close range, such as 5-7 yards, some are at breath distance (1 yard and less), and some are at further distances (10-30 yards). Learning when to draw your firearm without landing in jail afterwards and how to draw your firearm without shooting yourself or getting shot by the threat are essential components of any defensive handgun training class. Point shooting at breath distance and properly lining up your sights at any other distance is another component. Shooting at a moving threat while moving toward cover, toward or away from the threat, or just to make it harder for the threat to shoot you is another component. Proper reloading and malfunction clearance is yet another component. Drawing your firearm from various positions, including while sitting in the car, is yet another component. One-handed shooting and firearm manipulation would be yet another.
Most of these skills can be learned in a 1-2 full-day defensive handgun classes with a good school. These skills should be frequently practiced afterwards. None of these skills depend on the make and model of your firearm, other than a few differences in operating controls (e.g., manual safety vs. no manual safety), action type (e.g., single action vs. double action), and handgun type (revolver vs. semi-auto).
As far as your question regarding shooting groups at the range at 30+ feet goes, in a self defense situation, you should be shooting while moving toward cover or toward/away from the threat, potentially not shooting at all and just running toward cover, shooting from behind cover, or shooting from the kneeling or prone position when pinned down. This is all situation dependent. You definitely should not just stand there in your Weaver or Isosceles range stance and slowly shoot at the threat. That will likely get you killed. M.O.V.E = Motionless Operators Ventilate Easily.
