Shooting a pistol is not as easy as you may think. It is key to learn the basics of sight alignment and trigger pull in order to be an effective marksman.
When aiming a gun, you will need to put the front sight post in the notch of the rear sight, making sure that there is an equal gap on the right and left side of the front sight post. Also, the top of the front sight must be even with the rear sight. Focus on the front sight and put them both on your target where you want the bullet to hit. The rear sight and the target will be a little blurrier, but that’s okay. Your eye can only focus on one thing at a time.
When placing your finger on the trigger you will need to get it in a position where you can pull the trigger straight back to the rear of the gun. If you do not pull it straight back, you will pull or push your sights off target as you pull the trigger. If your shots are grouping to the left of the target then the trigger is too close to the tip of your finger, and you are pushing the sights off target as you pull the trigger, assuming you are right handed. If the shots are grouping to the left of the target your finger is to far on the trigger. You are pulling the sights off target as you pull the trigger. Keeping your finger as low as is comfortable on the trigger will make it easier to pull it. The trigger is nothing more than a lever. The lower you are on it, the more leverage you will get.