1. Go shoot a lot of different pistols in different calibers. A good range will let you try before you buy or apply the rental costs to the firearm you purchase. For carry guns try a glock, springfield xd, S&W M&P, Sig P320, ect. Don't let any mall ninja or online warrior tell you A firearm is better than B firearm. As long as it's quality made gun you're going to do just fine.
2. Buy whatever is the most comfortable and has the best point of aim. Meaning, what ever fits your hand well and is on target with out a lot of adjustment is the right gun for you.
3. Don't waste money on lights, lasers, and sights. Spend that money on ammo and range time. Muscle memory and weapon proficiency saves lives, not gizmos.