Honestly, at that age, they will not remember the trip. It's about spending time together as a family.
My kids' favorite park is Epcot. Why? Because my DH and I love (love) it! We just did what we thought we'd like, and took them to what they would enjoy. No matter what, you'll have a good time.
Of course, PLEASE do Winnie the Pooh! My DD loved the Teacups (but don't spin me PLEASE). If you don't spin it's nice (it was her first ride ever anywhere at 2).
It's a Small World is fine - they can sit on your lap. Dumbo I think I'd wait on. The character meals may be a bit much for that age. I'd just go with the flow and do what feels right. Take it easy (it'll be hot and rain periodically). The characters can be scary at that age - don't push it.
A lot of shows they can sit on your lap. Don't overdo it. The baby carrier may be hot - think sauna! A stroller is good, then a bit of carrying and walking (of course not too much walking). Drink lots of water - you can get extra ice water at any place that has fountain drinks.
Take your time and enjoy the little things!