Well, what do you need from a first pistol?
Answer: a good educational experience.
You are going to be learning a lot habits from this weapon. A lot of what you will be learning will be in the indelible ink of first impressions. This first pistol is going to be quite a learning platform.
Lesson one; safety. You need a pistol that doesn't have one. Switch safetys were created by the military for military purposes. Not the least of which is a lack of confidence in young men's ability to not be stupid. You need a pistol that you will always think of as being dangerous because they flipping well are. A switch safety will give you a false sense of security. So avoid a weapon with one. They are simply a bad idea for the most part, when you are talking about a personal defense weapon. Remember if you can get your weapon drawn and in action in one second...you are too damn slow and need to work on that. A switch safety will make that worse. Bottom line a pistol without a switch safety will foster a mindset that keeps your finger straight and off the freakin trigger.
Lesson two; maintenance; you will need a weapon that is easy to strip and easy to clean. You need to clean your weapon once a month. In addition to every time you fire it. So easy stripping is a must.
Lesson three; resale value. You are going to go through three pistols before you find the one you are really happy with. So it behooves you to buy your first pistol with a view towards selling it. Get something with a solid track record for retaining it's value.
Lesson four; accessories. You don't know what you are going to like in things like holsters, aftermarket magazines, aftermarket sights, aftermarket triggers...so on and so forth. So get something where there is a lot of that. Because you are going to be trying out a lot of these things to find out what works best for you.
On top of these lessons there are the more mundane problems of learning the fundamentals of pistol marksmanship. For that you will need something that is reliable out of the box. Small enough to carry but still big enough to shoot at the bad guys with a good chance of hitting them.
That applies to the ammo as well. You need something that you can afford (as in actual money) to shoot a lot of without leaving you in (either physical or financial) pain afterward These factors favor a smaller caliber. Yet since this is your defense pistol the caliber needs to be big enough to stop an attacker.
My recommendation to my acquaintance was, (yep, you guessed it), the dull one. The humble and rather unattractive:
Yes, this was the best looking picture I could find
Replace the sights with XS Big Dots.
Get your holster from Galco.
Use Federal for practice ammo but not for defense.
When it's Go Time, I recommend Cor Bon DPX.
Please bare in mind the Glock 19 is NOT perfection. It's not the best pistol out there although it's far from the worst. It just happens to hit the sweet spot on a number of bell curves for a conceal carry pistol. That does not make it perfect but it does make it a great choice for a first pistol.
Author's caveat: No I don't use a Glock 19 for my EDC. I have long since migrated to CZ.
Proof of how easy it is to field strip a Glock