Hi Shawn,
The crowds in the summer are always a bit busier because of summer break for the schools. I will say that we have been at Walt Disney World at busy times and it is still a fantastic time. Everyone is there will the same intention and that is to have a fun time!
I would really recommend visiting the Magic Kingdom, there is something for all ages there. You can easily spend more than a day there!
The other park that your kids would love would be Disney's Hollywood Studios.
At both parks there are so many fun attractions, shows, parades, character meet n greets.
My kids love going to character dining. It truly is a special experience.
HERE is more information on character dining.
Make sure and enjoy your resort as well. Relax at the pool or enjoy the amenities your resort offers.
A trip to
Downtown Disney is always fun. There are so many fun shops and restaurants.
There is so much to see and do. You will have such a fantastic time!
Thank you for your question.
Happy planning!
Carrie