Hi Stephanie!
Welcome to planDisney.
I recommend you use Mears Connect to travel from MCO (Orlando International Airport) to
Disney's Art of Animation Resort. You can make your reservations on their website, and I have always found them reliable and reasonably inexpensive (around $16 per adult and $13 per child -
prices subject to change). You can book your return trip to the airport at the same time, giving you one less thing to think about during your vacation. They usually book your pickup to the airport around 3 hours prior to your flight’s departure time, but you can choose a different time if you prefer.
For five passengers it's probably more value for money to take a Lyft rideshare from the airport. I have used them, and they arrived quickly and assisted with my luggage. The cost for a rideshare would be lower than Mears Connect for your family, but I'm not sure that car seats can be guaranteed. I would download the Lyft app to your phone and see if there's an option to request car seats.
Once you arrive at Walt Disney World you have all the complimentary
transport available for you to get around the resort. You will need to collapse your stroller on the buses and the smaller boats but you will find it an efficient way to travel around.
Please come back and visit us if you have any further questions. We are always happy to help you plan your magical vacation to Walt Disney World.
Sue