Hi Mildred,
How exciting to be planning your first visit to Walt Disney World! Let me help you out with some of your questions.
First, I do not think you can plan your trip wrong! There is so much to do at Walt Disney World, and every family is different in what they want to do. That said, given the ages of your children and that it is your first visit, I would absolutely recommend that you visit
Magic Kingdom! It is where the magic all began in Florida, and with the iconic Cinderella Castle, it is the theme park that most guests associate with Walt Disney World. Given the ages of your children, you will likely want to spend lots of time in Fantasyland, taking in wonderful attractions such as Under the Sea - Voyage of the Little Mermaid, Dumbo the Flying Elephant, and one of my favorites, Peter Pan's Flight.
As to transportation, if you are staying at a Walt Disney World resort hotel, you will find that the transportation to and from the theme parks runs continuously throughout the day. I find that
Disney buses tend to run at least once every 20 minutes. Depending on your resort, you also may be connected by
boat or
monorail, both of which also run frequently.
Finally, I suggest that you check out the
Walt Disney World for Little Ones planning page. This page will give you lots of tips for your trip with your children.
I hope that these thoughts are helpful for you, Mildred! Please do let us know if you have any further questions.