Hey howdy hey Virginia and welcome to planDisney!
I am so excited that you are in the process of planning a trip to visit Walt Disney World Resort soon. The process of planning a trip is such a fun and exciting part of the whole vacation so let's talk about these parks!
With four Theme Parks and two Water Parks, Walt Disney World has so much to experience that is very important to prioritize your trip, the parks and dining reservations, based on what your kids like and will enjoy. As a girldad of three, with my kids very similar ages as yours, they all have their own special interests. Some like slower-moving and more relaxing rides while my middle daughter is a thrill seeker and loves all of the roller coasters. We find that we have the best times in Magic Kingdom and Hollywood Studios as the two of our favorite parks.
Magic Kingdom is the original park that has so many of the classic Disney attractions such as "it's a small world" and Pirates of the Caribbean. It also has some of the more thrilling attractions such as "Space Mountain" and "Big Thunder Mountain Railroad" for those adventurous riders. This park has five themed lands and the most attractions of any other park and will surely have something for everyone on your trip.
Hollywood Studios would be my second pick. So many new additions with the expansion of the park including
Toy Story Land and
Star Wars Galaxy's Edge have experiences unlike any other. Playing some classic games with a 3D experience at Toy Story Mania! you might want to do this one a couple of times, it is so much fun! In Galaxy's Edge, Star Wars: Rise of the Resistance is one my older two and I got to experience together and even though they are not big fans of Star Wars, they absolutely loved it. There is so much to experience here for kids of any age that I would highly suggest this as a strong second from me. I would be remiss if I did not mention Mickey and Minnie's Runaway Railway. Mickey and Minnie themselves star in this train ride that gets away from Goofy for a wild and unforgettable experience!
Animal Kingdom is a great park to visit with a lot to see. My daughters are not really into animals much so it is one that we do not prioritize. EPCOT is currently undergoing a big transformation to the park itself so there is quite a bit of construction. Out of all of the parks, this one is more of the "adult" parks with all of the food, drinks, entertainment available, it is entertaining and there are things to do, just not as up-to-date as other parks at this time.
I hope this helps give you an idea of how to best plan for your park selections. No matter which parks you choose, you are in for an unforgettable experience in the Most Magical Place on Earth! Let us know if you have any other questions, we love talking about all things Disney!
Happy planning,
Nick