Hello, Sreeram! Thank you for coming
planDisney.
I think four is one of the most magical ages for a
Walt Disney World vacation. My kids at that age were less leery of the characters, but they still fully believed everything they saw was real. So many happy memories!
Your best bet on a budget for transportation between Orlando International Airport to your resort is going to be one of the shuttle services. Mears Connect is probably the best-known option, but you'll have to go to their website to enter your resort information to price the trip. Mears also runs private cars, but those generally are a bit pricier.
Rideshare services, such as Uber or Lyft are also an option.
In Florida, car seat requirements "do not apply to a chauffeur-driven taxi, limousine, sedan, van, bus, motor coach, or other passenger vehicle if the operator and the motor vehicle are hired and used for the transportation of persons for compensation." This basically means that pretty much any paid service is not required to use a car seat. However, most rideshare services won't drive a child without one. Uber has Uber Car Seat, which will provide one car seat, and the cost is the same as UberX, plus a $10 surcharge for the use of the car seat. I'd also search Google for taxi services, which may be a little more expensive, but some do provide a car seat at no additional charge.
Also, Sreeram, check with your resort. There's a chance they have a shuttle that provides airport transportation.
I hope your trip is amazing!
Anna