Which park is better for Disney World for my 2 year old?

Ok so I am going to Disney World with my son for his 2nd birthday. I know this is too early an age BUT I got FREE Disney Tickets....FREE Hotel.....and FREE airfare. How can I p it up right? So I know that I want to go to Animal Kingdom because all little kids love animals and I personally think it'll be a nice adventure! Maybe not too much walking.....seems like alot of car rides or tour type things. But I am not sure which I want to go to for the second park. We have FREE tickets to 2 parks. Now, my son loves Toy Story and Cars so Disney Hollywood Studios fits that.....only thing is, is that my son hates the Easter Bunny and things like that make him cry. I am leaning towards Magic Kingdom but I just don't know. So if you have any suggestions and you are familiar with Disney World please help me out. thanks