I try to keep it lite.
I use a "fanny" pack for photo gear which will have an extra battery, memory card and a circular polarizing filter. I always have a 50mm f/1.8 (Nifty Fifty) in the bag as it's very light and takes up little space. A Nikon Speedlight (Flash Unit) for outdoor Fill Flash of people and indoor photos where allowed. I may swap out the flash for a Wide Angle Zoom if I have plans on using one.
I carry my Nikon D750 camera with either one of two lenses: Nikon 24-120VR f/4 or Nikon 28-300VR f/3.5-5.6. It will depend on the park of the day. Definitely the longer lens if going to Animal Kingdom.
If I plan on doing any long exposure low light photography of the parks or firework shows, I bring in a tripod and rent a Large Locker for the day to put it in. I then go pick up the tripod when I need it later.
I have been known to bring in a bigger zoom (like the Nikon 80-400VR) to Animal Kingdom. Again, I rent a locker if I am not going to use it all day.