If you go to a CAS event only partially armed, chances are that someone will let you borrow a gun that you need. There are many good discount firearms dealers who will be glad to help you get started. Some even have web pages. I have gotten excellent service from Discount Guns Warehouse in Houston, Texas. Their prices are very reasonable, and they ship quickly.
Most shooters also have a gun cart to carry their guns and other equipment.
Some of these are quite ornate. To see what mine looks like, click here. Well, it can be. However, CAS participants are meticulous about gun safety. All actual shooting is done on a closely supervised gun range.