Try not to take a lot of cash. Credit cards are accepted in most places, and travelers checks are considered as cash. Pack as light as possible. Most people use very few of the clothes they bring, and many hotels and campgrounds have laundry facilities. You will not need many dress clothes or much jewelry.
Casual dressing is acceptable in nearly all restaurants and dinner shows.
Packing light will allow you to leave space for all the things you will purchase. A small backpack is helpful to carry rain ponchos in case a sudden rainstorm erupts. They are frequent in Florida, particularly in the summer months. Bring plenty of sunscreen on your trip. You might be surprised on the various activities in which you can get a sunburn.