Welcome to the group. We don't usually camp in hot weather,but do travel through some.
I always leave the front slider open a few inches and the roof vent open slightly to give a bit of air flow.
I have found that the camper actually stays cooler than the outside temp.The white of the camper does reflect the sun and doesn't store heat.
I find also at home and not camping ,when we have some very hot days the camper also stays cooler than the outside temp.
One thing about opening the vent ,open it only a little if you are driving the air at speed over the vent could rip off the cover
or at least damage it.
Frank