Side, hip, thigh holster would be fine.
This is what I usually bring when I attend a shooting class.
Double Mag Pouch
side, hip or thigh holster
eye & ear protection
baseball cap/bonnie hat
dump pouch (store extra full/expended mags and loose ammo)
You don't need to buy everything if you don't have it. You can always substitute with something else. Ex. Cargo pants or fanny pack in lieu of the dump pouch. Knee pads aren't necessary but the terrain at Burro is a bit rocky and after a few times you go to the knee position you'll be glad you have them. It's more of a creature comfort.
Don't forget sunscreen, refreshments, lunch, pen and note pad for note taking. It's forecasted to be 81 degrees in Azusa on Saturday so bring plenty of cold drinks.
I was in Chino Hill's last weekend for a level 2 pistol class and it was 85 degrees out there. I went thru 2 medium size bottles of power aid, 4 medium size bottles of water and 2 boxes of coconut water. It was barely enough. Basically bring extra cold drinks, you can always bring what's leftover home, or aid a fellow calgunner out who didn't bring enough.
Above all else, have an open mind, have fun and be safe. Any day where you get to shoot at least 200-300 rounds of ammo is definitely going to be a good day.