We've just got back from our newest little Princesses first Disney trip (spoilt with wdw!) and she was just the same, absolutely adored the characters from the moment she saw Stitch at breakfast on our very first morning! I was a little worried before hand, only as I remember DS on his first trip to DLP was a little apprenhensive to begin with (but got there in the end thank goodness!)
So it's been a couple of years since we've done DLP with a toddler but we've not done it without one for 10 years now either!
Hit... Small world (always first for us) Peter Pan and yes leave Snow White til last if you do it, so if it does frighten them a little bit, they know that not all the rides are like that! Ours funnily enough weren't scared at all (at 3 and 1 when we first went) but I can definitely see how it could be for some. Disney Junior Live and Animagique (one of my faves too so was very happy that DS loved it)
Slinky Dog, Cars rally and POTC were all very popular with DS from around 2 onwards too. DD1 loved Dumbo (but me not so much due to the long queues)
Avoid... character scrums, not fun when you're tiny, although I'm hearing good things about this changing at DLP so I'm hopeful for our trip next spring! Character meals are a much more enjoyable way of them meeting the characters and all our best interactions have been at those anyway.
Also, make full use of EMH and head back for naps during the peak times! Best thing we did when our older two were little, the bonus with a tiny one is that they will sleep in their pushchair but there's nothing like a proper recharge half way through the day. This way you should be able to stay later into the evening to see Dreams etc without a unhappy LO.
Take plenty of snacks, I always have raisin boxes, crackers, cartons of juice etc in the bag, another bonus with a LO is room in the pushchair basket and no need to carry the heavy bags full of snacks!
Hope this helps a little! Sorry if it's all completely obvious, I do waffle on! (especially when I'm stuck on the graveyard shift!)