[Jim243]

Welcome to the forum. You are shooting a 9 mm if using a G19. Different weight bullets will have different points of impact. Heavier bullets will impact higher than lighter bullets with the same point of aim.

For 9 mm I like the 124 grain bullets, but 115 grain ones are more common.

Guns are funny, some like one brand of ammo and then others like different ones, you will need to try out different brands and configurations (FMJ), hollow points, round nose, flat point, semi-jacketed, etc... till you find the ones that work best in your gun and barrel. (this is normal)

You indicated that you were starting out a 10 yards (30 feet). Defensive handgun shooting should be measured in feet instead of yards. Most defensive shooting is short range. I would recommend that you start at 10 feet and then move out to 20 feet and finally 30 feet (10 Yards).

If you have a proper grip on your pistol, then forget about the rear sight. You need to concentrate on the front sight only (especially since you wear glasses) your eyes will not focus on both sets of sights at the same time. It is the front sight that is important. Hold your front sight directly on the center of the bullseye and shoot 5 rounds (slowly) if you are still hitting high then lower your front sight to a 6 o'clock hold just UNDER the bullseye. Use the tip of your trigger finger instead of wrapping it around the trigger and get the feel of how and when it will fire. (this is trigger control) Your shots then should not be going high right.

Start slow aimed fire and then work your way up to rapid double taps. With practice at 10, 20 & 30 feet you will get better as you learn the gun and how it shoots.

Good luck and stay safe.
Jim