the beginning and end of Summer looks very different for us. I actually try and do more camps and vacations towards the end of Summer when it's hot, everyone is sick of swimming and we're limping across the finish line.
June we lay low, do swim team and recover from the school year. It's also not as hot and more manageable overall.
As far as working I would try to carpool on camp drop off/pick ups and create a loose rotation of other working moms where you can each take an afternoon after camp to help each other with childcare/playdates.
I also try to have a few days a week where my kids get a break from one another. Whether that's camp, play dates etc
Having a couple activities a week planned is helpful too. Write it on a calendar so the kids know what's coming. Even if it's a splashpad, different pool or movie etc