Often and Safely! Seriously, the theory is that it takes 1000 repetitions to make a habit. That is a lot! But, it can take 2-3 times that to change a habit. So, practice, practice, practice, but do it right! If in doubt, consult a qualified instructor, to ensure that you are not locking in any bad habits.
Many instructors recommend dry firing. Dry Fire is firing your gun without a round in the chamber, or with a dummy (non-firing round, usually plastic) round. You need to be VERY careful. First, consult your owner’s manual to ensure that Dry Fire isn’t discouraged for your pistol. Then you need to ensure you have a safe direction for aiming. There are several websites that offer suggestions for how to set up a safe dry fire area. One of the most important steps, before ever pulling the trigger, is to ensure, visually and physically, that your gun is not loaded. Then, check it again! Do not have live ammunition anywhere near where you practice your dry fire area to avoid an accident.
So, why dry fire? It is good practice. It doesn’t cost anything. You can practice your stance, grip, drawing, aiming…build your muscle memory and the skills you develop at home translate when you are at a range and able to live fire.
New shooters should try to shoot at least once a week. Start your target at about eight feet, gain confidence, then gradually move it further out, in increments of a few feet, to 15 or 20 feet. Then, bring it back in. The closer target builds confidence, the distance helps you to see what mistakes you might be making. If you are shooting high, you might be heeling, or gripping too hard forcing the front of the gun to rise. If you are shooting low, you might be anticipating the recoil. Right handers who shoot to the left, may need to work on their trigger control. Left handers, just the opposite.
When you are building your strength you may only shoot for 30 or 40 minutes, or 50 rounds. That’s ok! This is fun, it shouldn’t be painful. As you get stronger, you can shoot longer, or more rounds.