First off, go to a match. Watch and ask questions. You don't have to shoot if you don't want to. See if it's what you want to do. See what equipment folks are using. Don't worry about the clothing etc.
There are different sanctionging groups out there that represent CAS shooting. They vary in how authentic they are. SASS (
www.sassnet.com) is by far the big guy on the block. They have a club locator if you don't know of any clubs nearby.
If you decide that it's for you, go shoot a match. Just let the match director know that it's your first match. Most likely there will be several folks who will offer to squad up with you to lend you whatever you need. My first match I didn't have a shotgun. I had half a dozen people offer me one of theirs for the match. I wore jeans, snap button western shirt, work boots and one of my cowboy hats. Where I shoot now, we're not too concerned on how a new shooter dresses. We've had a couple of new shooters show up in jeans, t-shirt and ball cap. We don't mind that on their first shoot but let them know that's not really correct. If they want to shoot the next month, at least ditch the ballcap and t-shirt. The X-Marts and farm and home supply stores all sell cheap hats and western style shirts. We've also got several shooters that bring along extra guns (or sets of guns) just in case a new shooter wants to try it out and has no firearms.
Make no mistake, it can get expensive to play the game if you let it. CAS shooting usually requires two single action handguns, a main match rifle and a shotgun.
The shotgun can be a visible hammer shotgun, a hammerless (but no ejectors) shotgun, a lever action shotgun or a pump shotgun with a visible hammer (1897 etc). Most folks here shoot hammerless doubles (least expensive) or 1897s though we have a couple of shooters that use 1887s or hammer doubles.
For the rifle, the majority shoot Marlin or Winchester, though Rossi is well represented also. There's also one shooter that uses a replica of a Colt revolving carbine (just for fun, gets his butt whipped on reloads
). Also most shooters use the same caliber as their handguns. Decreases the logistical nightmare.
Handguns run the gamut of what's out there, as long as it is within the rules of caliber and velocity.
After you have your main match guns, there are the side match guns. These are optional in that they are not required for the main matches. They include the long range rifle, derringer and/or pocket pistol.
So as I said earlier, it can become as expensive as you want. If you find that you like it, don't worry about getting everything at once. Just go shooting to have a good time and gradually build up your equipment.
And once you have your firearms down pat, the rest is another whole ballgame. We've got shooters who have two and three complete sets of firearms so they don't shoot the same guns month after month. Some of our shooters even have half a dozen outfits so they never come dressed the same during the year! Most everyone still has only one guncart, though two shooters that I know of have two (they are motorized).