I always encourage people who are new to firearms to go to a local range and rent a few pistols. Many ranges have a "free gun rental night". You can speak with the counter person, handle a bunch of pistols then rent a few that feel the most natural to you. If you plan to shoot regularly, i always recommend a 9mm. Range ammo is the cheapest of 380, 40 and 45 and when you're carrying it, there are some fantastic newer technology bullets like the hornaday critical duty +P, Federal HST and a few others that perform nearly identical to .40 rounds.