Learn on a 9mm if you must start with a semiauto pistol. Your good shooting habits will be much easier to learn with a softer shooting 9mm. With HP ammo, 9mm is quite effective. It’s shortcoming is when it is applied to our military, and they must use full metal jacket (nonexpanding) ammo.
If you get a 9mm and practice a lot and want more, only then move on to a .40 or .45, when your good habits are established. If you start on a .45, you may learn a flinch, and be a rotten shot forever. A hit with a 9mm is 100X better than a miss from a .45.
Thanks for the advice though I have owned numerous 9’s and 45’s over the years and have never been any good with them outside 20 yards.
I will take a look at the glocks though since all I have owned are colts, walthers and brownings.