Revolver vs semi-auto for a first carry gun?

A revolver is dead simple and reliable, but it holds only 5-6 rounds, reloads slowly, and has a long heavy trigger that is genuinely hard to shoot well — which trips up a lot of new shooters. A slim modern 9mm semi-auto gives you more rounds, faster reloads, a lighter trigger, and easier sights, at the cost of learning the manual of arms. For most people willing to train a little, the semi-auto is the better primary; keep the revolver as a simple pocket backup.