100% a DA gun will teach you things about trigger control that you'll never learn from a Glock. However, I also think there's value in the SA pull as well. Sure, it's short and light, but you can snatch it just as easily as you can any other trigger.
I'd go classic Sig or Beretta if I were you.
Food Court Apprentice
Semper Paratus certified AR15 armorer
I love revolvers, but most of your suitable choices will be .38 special, which is 2x the price of 9mm. If you want the skill derived from a da trigger but actually want practice making it go bang, your dao semi-auto (or da/sa) would be cheaper in the long run.
In my opinion a DA revolver will make you a better shooter. The concentration required to make everything work each and every time is invaluable. Once you master the DA revolver the Glock "safe action" or the trigger on my SIG P365 are easy to operate. My son wanted to shoot all the "cool pistols" but I started him on a S&W M17 to work on his targeting through the trigger stroke. He thanks me for it now.
I know the prices today are way higher. I was quietly buying them when everyone was transitioning to pistols. Found a similar deal on a LNIB 3" RB Mod 10-8 with all papers and an intact box. It pays to buy your LGS guy/gal a bottle of their favorite when they bird dog the things you covet.
"You win 100% of the fights you avoid. If you're not there when it happens, you don't lose." - William Aprill
"I've owned a guitar for 31 years and that sure hasn't made me a musician, let alone an expert. It's made me a guy who owns a guitar."- BBI