Welcome to the sport. I shoot mostly uspsa but do shoot idpa a little. I am running a cz 75sp01 with a leupold dp pro in the carry optics division. Most common guns I see are cz, Glock, Smith Wesson, or the custom 2011. Belt I use is a 511 tactical for idpa (stiff) to support weight of gun and mags. Uspsa is a double alpha. Holster for idpa is a Daranich Tactical kydex, uspsa is a Red Hill Tactical, idpa mag pouches are comp-tac, they also make nice holster(popular). Uspsa mag pouches are Ghost 360 mag pouches.
Take a look at practiscore.com, you can search your area for events and is used to register for most events.
Also Tacticalpoppins.com, this will give you most events in Houston and surrounding areas.
I recommend shooting equipment that you currently have for a few month. At the matches ask to look and feel all the other guys stuff to figure out what you like and what division you want to shoot in. ( this will save a lot of money)
I shoot most Monday’s in Alvin at Big Kountry range