Gun, holster, mag carrier, 400rds of ammo, eye & ear protection, check for $150. The registration form will have the details.
I don't remember if he specified a holster type or not. Everyone I saw was using a strong-side, so I don't know if he would have allowed a crossdraw or shoulder holster or not. One lady had a "thunderwear" type as well as a regular belt holster and he had her use the belt one for the class. I used a Kahr 9mm and the Galco IWB the seller included with it. You'll need a way to carry at least one spare magazine too. I used a Fobus double carrier for the class.
I think he specified factory ammo. I used Win USA bulk from Wally World. He said bring 400rds but I think we only shot about 250. He'll let you pick up your brass, but don't expect to get any back. At the end of the class everybody will go out and police the range and I got maybe a couple dozen cases back. (All of the brass is saved and traded in for training ammo for the dept. so just consider it a donation to help keep the classes going.)
IIRC the application asked for gun type, so he'll probably tell you when you sign up if you can bring what you have. First thing he did on the first day (after lunch, the morning was classroom) was have everybody holster up and he and Brent went down the line checking out what everybody had.
No need for knee or elbow pads or gloves or anything like that. Wear comfortable shoes/boots since you'll be standing pretty much all afternoon the first day and all of the second day. Dress for the weather since they'll shoot rain or shine. (We had upper 70s and sunny.) Sunscreen and a hat are a good idea. The range has a covered area with picnic tables where you'll load mags between relays but the range itself isn't covered. I think he provided water outside and maybe coffee in the classroom (I don't drink coffee, so didn't pay too much attention). Everyone got a notepad, folder, pen, gun lock, and some other odds n ends in the classroom.