Get ready to sweat! Lol. We've been to USA Baseball Championships 3times, Wilson Classic and a PG championship of some kind, and AZ Fall Classic. All held at MLB facilities, so we've done summer in AZ a few times
. Although honestly I've forgotten which ones the R/R are.
Bring your own shade and a chair. (sorry probably not the answer you wanted) Some of the seating at these events is minimal and usually the areas directly behind home plate is reserved for scouts. You could probably get away with a stadium chair and an umbrella, but a few fields don't have any seating or it's a small bleacher area at best, so you'll have to "play nice" with other fans and their umbrellas. I prefer the foldout chairs that have a mesh inset, they're a little cooler and a freestanding umbrella that's adjustable. (RE area for scouts: It's not labeled, so if there are scouts at your event, DON'T sit there). Some of the fields have overhead shade but frequently it's not over the (small) stands. A few tips: be careful about what you wear. I tend to wear running gear simply because I have it and it breaths. Cooling towels, both for you and your player. Light color hiking hat that can get wet (cooled down) is nice if it's REALLY hot for you. Pedialyte is your friend, try to decrease sugar and caffeine for your guy leading up to the event. I can't imagine doing it, for a mid day game, without a cooler. Maybe a cheap one? Or maybe check out a Play-It-Again sports type place? I guess we are lucky to be in SoCal so we drive over with all the gear.
Best of luck!