I'll reiterate what others have said: 1) Check out some different guns in hand and see what feels best, and then 2) Rent the ones that fit your hand right if you are able and see if you are comfortable shooting them.
For my first handgun I was pretty much set on a Glock due to it's reliability. Initially, I wanted a Glock 26 (sub-compact 9mm, holds 10+1). I was advised on another forum to start off with a full size weapon by the majority of participants, so I went with a Glock 19 (Compact 9mm, holds 15+1). The Glock 19 felt okay in my hands but when it came to range time I never really felt comfortable with it. Accuracy suffered as a result. I was able to trade it in for a 26 and the difference is night and day with how comfortable it is to shoot for me.
For my first handgun I was pretty much set on a Glock due to it's reliability. Initially, I wanted a Glock 26 (sub-compact 9mm, holds 10+1). I was advised on another forum to start off with a full size weapon by the majority of participants, so I went with a Glock 19 (Compact 9mm, holds 15+1). The Glock 19 felt okay in my hands but when it came to range time I never really felt comfortable with it. Accuracy suffered as a result. I was able to trade it in for a 26 and the difference is night and day with how comfortable it is to shoot for me.