You should find out how you can directly buy a Firearm before buying it. Hold the empty gun and hold it in a safe position, with the finger next to the trigger (not exactly above it). Go to a fixed target. Open your eyes or the objects you should see where you want them to be. At a distance of 4.5 meters, your position should not be more than a few centimeters from the center of the target.
Try a variety of firearms whenever possible. Use a handgun that feels good in your hand when you shoot, otherwise the "more accurate" model might not work.
Think carefully about whether you can pull the trigger on other humans or not. Apparently pulling a firearm is a good idea, and it does not matter.
In Design Firearms 3.9