Hi and welcome to the Moms Panel! The first family vacation to Walt Disney World is very special!
Where you stay depends on a couple of factors, primarily what your budget is (there are Value, Moderate, and Deluxe resorts at Walt Disney World Resort) and how many are in your family, as some resort rooms can only sleep up to four guests plus a child under three.
As for parks, my opinion is that Magic Kingdom is a must and great for all ages. Hollywood Studios, Animal Kingdom, and Epcot, each have their appeal and are easily enjoyable for the kids in my family, too.
There are parades and at some parks there are fireworks, too. To get you started on finding those for the dates/parks you might be attending, check out the Calender available on the Disney World website, as I explained to another guest in another question
here.
I'd love to help you sort through all the info you might find helpful, but in the space allotted I can only write so much! Please feel free to write follow up questions so we can help you!