It depends on the class and what you're training for. Typical class I would take a belt with a couple pistol/rifle pouches and a holster. All classes I took had trained EMS with full FAKs on the line, so no BOK on my gear. You will learn more if you're not working around your equipment. Less is better IMO.

10+ loaded mags; 20 if you can, for rifle.  Half that for pistol.

Nothing wrong with a "war belt" if it's part of your setup and you keep it set up to go in real life.  Depending on the instruction, I'd want 3 rifle and 2 pistol spare mags on my body.

If you have a chest rig, no reason not to use it.  Also no reason to buy one for the class.  In fact, the class will be an opportunity to watch other guys, see what works, talk to the instructor.ld

In my area, AZ, water and a means of accessing it without having to step out of the "circle" of instruction.  Drink WAY more than you think you need to.

Sunscreen; hat, eyewear for different light conditions.

Gloves, boots/footwear.  Gloves-- whether for hot guns or cold weather.  TWO kneepads; elbow pads maybe, but try them first.

If you are in ketosis (metabolic state), time your protein consumption based on your personal patterns.  For me, it'd be eggs/bacon for breakfast, and big juicy cheeseburger (I discard the top of the bun) for lunch.  If you are still a sugar burner, do half your usual caffeine in the morning to avoid deydration and shaky early morning accuracy drills.  If you dehydrate and spike your sugar, you will suffer.


If you tolerate Gatorade, okay; I don't, so some salty bacon in the morning sets me up for avoiding dehydration and the loss of electrolytes.

Don't drink (much) alcohol the night before.

If you're overweight, do what you can to pull your shit together so you're not the slowest guy in the class.

Read about the techniques/instructions you will experience.

I know you said minimalist; I'm basing the above on my personal experience.  These are the things I WISHED I had my first time, and I got them for subsequent classes.

ETA electronic ears.  I'm a double-protection guy (musician who uses hearing daily for work, so I do plugs and muffs while shooting).