Hi Valerie,
The Walt Disney World Resorts usually has one water park open for guests.
For the older kids, 10 and up, I like
Typhoon Lagoon, and this park will be the only one open during your vacation. The wave pool is like being at the beach. Select mornings prior to opening they offer surf lessons. There are also water roller coasters and a coral reef you can snorkel with fish, sharks and stingrays. For the younger children, I like Blizzard Beach because it has tons of family rides and great children's area. However both are fun for children of all ages.
As for weather, it is usually in the high 60's/low 70's but you could have an 80 degree day. I always check the weather prior to leaving. I would pack pants and light coat as it does get chilly at night.
As for cute shoes, cute is a relative term. Some people do like the CROCS mary janes. I like Birkenstocks because they keep my feet cool and comfortable. If I wear sneakers, I always use wick away or moisture removing socks to keep my feet dry. I know some moms like the Fit Flop shoe as well.
Wishing you a magical day!
Beth