Since the kids are older, I will assume they are past the age of the character meet and greets of Magic Kingdom. If they like rides, then take your pick of the Universal parks, Sea World, or Busch Gardens over in Tampa about 90 minutes away from the Disney area.
Don't forget that we also have some great water parks, which will be nice in July.
You can also visit a spring, like Blue Springs State Park, and swim in the 72 degree crystal clear water and see some of FL's natural beauty.
For beaches, my personal preference from Orlando is New Smyrna Beach on the Atlantic side. We drive onto the beach, throw up a canopy tent, pull out the cooler and relax for the day. For finer sand and warmer and calmer water, head to Clearwater Beach, but it's a little further away on the Gulf side.
Our check out this place;
https://www.revolutionoffroad.com I have been on their property at least a half dozen times for obstacle course races. While I have never rented their ATV / RZR's, I have friends who have been and loved it.
Or check out this place;
https://www.orlandowatersports.com You can learn how to wakeboard, or play on the floating obstacle course all day in the hot sun.