Hello Sarah! Thank you so much for visiting us here at the Disney Parks Moms Panel.
Disney's Pop Century Resort is such a fun place to stay, we've stayed there many times. I also love the breakfast at Cape May Cafe, it looks like your vacation is going to be a great time. The pool at Disney's Beach Club is only for Guests staying at that resort. Same goes for any of the other Walt Disney World Resort pools. You are more than welcome, after breakfast, to stay and look around the resort, hit up the gift shop or venture out to the Boardwalk area but you wont have access to swim in the pool.
If it is a beach day you are looking for, I suggest checking out
Disney's Typhoon Lagoon Water Park. Disney's Typhoon Lagoon is my absolute favorite water park, it is a blast. You will get the beach vibe here with the sandy beaches, lush greenery and a wave pool with waves so big you can actually surf on them!
If you have any other questions about your Walt Disney World vacation,
please feel free to ask me. Have a great day!