What to Wear to Disney?

Hi! I'm heading to Orlando this December for a Disney World trip and it's supposed to be highs in the mid 60s to low 70s and lows of the low 50s.

What should I pack? We'll be there all day everyday for about a week and I'm worried about us getting too hot wearing kg jeans all day but I don't want us to be cold either at night wearing shorts.

I'm just unsure.