Hi Joyce! You'll certainly be able to enjoy the pools after you arrive at Pop Century. Lifeguards are on duty from 8 am until 10 pm. The pools are open until midnight, although no lifeguards are on duty.
On May 22, the Magic Kingdom has Extra Magic Hours. As guests of a Disney resort, you can enjoy extended hours, and on your arrival day, the Magic Kingdom is open until 3 am! This leaves lots of time, if you're not too tired! We love doing the Magic Kingdom late at night, especially Big Thunder Mountain Railroad.
One of our arrival day traditions is visiting
Downtown Disney. We always enjoy a fabulous meal and some shopping - you can even get a bird's eye view of Disney World, floating 400 feet about all the action on Characters in Flight. Buses run to and from Downtown Disney into the wee hours.
Have a magical vacation Joyce!