This is not a good question for me as the number of guns I have surpassed the “need” a long time ago. That said, I would like to get into some experiences I had with some people new to guns and new to carry that really apply.
First, I had a plant manager who jumped in to carrying with both feet. Got himself a Glock 23 and loved it. Loved to shoot it, but its a small gun. From getting more into shooting, I eventually convinced him that he needed a Glock 19 also. Why? Because his only gun was his carry gun. Now he has a gun that is very similar but is more comfortable to shoot for long periods of time when he goes out shooting with those of us who can shoot for hours on end. He ended up using that also for defense, it is just in his office at home in case he is too far from his EDC in his bedroom in his house.
Another friend that I got into shooting started out with a S&W SV40. Good starter gun for him, large enough to shoot for extended range sessions. However, he struggles a bit with his marksmanship. He also acquired a compact Ruger 9mm for easier carry, but also, not the easiest to shoot. So, what to do? Simple. Took him to the range and he spent some time behind one of my Ruger Mk IV’s, good trigger, easy to shoot, got him shooting well and the time behind the .22 really helped build confidence and fundamentals. So, what did he do? On the way home from my gun club, we stopped at a gun shop and he bought a good .22.
We are all in different places, and different priorities. These are just some examples from my life.