Hi Kacie,
My daughter was almost two when we brought her to Walt Disney World Resort for her first visit, and I had the same questions as you. Let me tell you that it was the best decision I have ever made! My daughter had the time of her life! I truly believe that our trip helped my daughter build her self-confidence and helped her with her extreme shyness.
My advice to you when planning your vacation is to stick to your daughter's schedule as much as possible. Book your dining reservations as close to her regular mealtimes as possible, and if she still naps, plan for some downtime as well. In terms of booking in advance, I would definitely recommend to book some dining reservations. For classic Disney character's I suggest Chef Mickeys, where Mickey, Minnie, Donald, Goofy and Pluto will come and visit your table. The Crystal Palace has characters from Winnie the Pooh, and is a favourite of my daughters.
For your daughter's age, I would recommend spending most of your time in the
Magic Kingdom Park. Here your daughter will love Prince Charming Regal Carousel, it's a small world, Dumbo The Flying Elephant, The Many Adventures of Winnie the Pooh, Enchanted Tales With Belle and Under The Sea ~ Journey of the Little Mermaid, to name a few!
At Disney's Hollywood Studios, be sure to check out Disney Junior - Live on Stage! Your daughter will be able to dance and sing along with some of Disney Junior's biggest stars! Disney's Animal Kingdom is also a great place for your daughter to see some exotic animals, as well as some fabulous musical shows.
i am afraid I have run out of space Kacie. Please let me know if you would like some more specific tips or suggestions for a possible itinerary when planning your trip. I would be happy to help!