[darkgael]

Just go shoot. The people that you will meet at matches are helpful and accepting of anyone who is serious about entering the sport.
As most posters have commented, much of what will happen depends on your choice of competition.
Bullseye match shooting (also called Conventional Pistol to differentiate it from International Pistol) has three gun match shooting (.22/Centerfire/.45). You'd have to have a .22 and a .45 to shoot all three but.....you can shoot the Centerfire match with your Glock. (Before she got too busy, we had an FBI agent shooting in our indoor pistol league; she used her duty gun for Centerfire, a 40S&W.)
One thing that you will notice once you start competitions is that standards for accuracy are way different than the normal range trip. The shooting that the Masters/High Masters do borders on magical.
Match shooting is absolutely the best practice.
Pete