We don't know OP's motivations.
BTW, my wife insisted taking my then 3 year old son to WDW (because she wanted to go) when she was staying in the area visiting relatives, and it turned out to be an expensive 2 hours--that's the amount of time it took him to be bored and scared at the same time. She didn't get to have fun either, and the memories are of a total--and expensive--bust.
I'd save your hard-earned money and spend time instead somewhere that's more interesting and constructive to kids of that age. Like the zoo. Or a wildlife preserve. Or a children's museum. Or an aquarium. We have some great memories of him discovering --and being amazed at -- jellyfishes.