Hi Daniel,
You and your family will have a fantastic time!!
Make sure you check the long range forecast before you leave so you can see what the weather will be like so you can pack accordingly (hats, sunglasses, sunscreen)
Make sure you bring our camera, your 4 yr old is going to be thrilled!! You will want to catch as many moments as possible!
I am not sure if you have made any dining reservations. My 3 kids all love character dining, it is such a fun experience that if you can do it you should!!
HERE is the link for more information or you can call 407 WDW DINE
When you arrive, make sure to pick up a Times Guide so you can see all parade, show and firework times.
Make sure to spend some time at your resort pool. It is a great way to relax and unwind after a busy day.
Take the bus to Downtown Disney as well. There are so many fun and unique shops and restaurants.
I am not sure if you are bringing a stroller or not. Each of the parks as well as Downtown Disney have stroller rentals.
You will have an incredible time!!!
Wishing you a very magical vacation!
Carrie