Hi Justin!
There are just a few weeks left before you are on your magical vacation! You will in fact be able to see fireworks, which I think are incredible and not to be missed! I checked the Calendar and found the following information about when you can see
Wishes Nighttime Spectacular in the Magic Kingdom,
IllumiNations: Reflections of Earth in Epcot, and
Fantasmic! in Hollywood Studios:
Wishes:
May 27th at 10pm
May 28th at 9pm
May 29th at 10pm
May 30th at 10pm
May 31st at 10pm
IllumiNations:
9pm every evening
Fantasmic!:
May 29th at 9pm, and 10:30pm
May 30th at 9pm, and 10:30pm
As for the wagon, you won't be permitted to bring it into the park, but you can rent a stroller if you need to at the parks.
Hope this helps!