Hi Judy,
Welcome to the Disney Parks Moms Panel!
Disney's Blizzard Beach Water Park is pretty much the coolest water park I've ever visited, but even with all the frigid fun, it's still a great idea to find a spot where you can rest and relax out of the sun. Luckily, it's been my experience that there are quite a few chairs to be found in the shade at Blizzard Beach, especially if you arrive early in the day. Those are available at no charge on a first-come basis, and on busy days they do fill up quickly.
If you want to be sure you have it made in the shade, there are a couple of options for renting a reserved spot. The first is a Lodge Picnic Umbrella, which offers 2 reclining lounge chairs, a table, an umbrella and towels for your group. Up to 4 people can use each reserved space. For something even more indulgent, you can get a Polar Patio. This is a reserved area in the shade for up to 6 people (or up to 10 for an extra charge), complete with cushioned seating, a personal locker, drink mugs you can refill all day long, towels, a cooler stocked with ice and bottled water, and even an attendant. You can reserve either option up to 180 days in advance by calling one of the great Cast Members at (407) WDW-PLAY (939-7529). Same-day rentals may also be available at the water park, depending on availability.
I hope that helps answer your question, Judy, and wishing you a magical day!
Beth