Hi Fatjona! How exciting for you to visit Walt Disney World for the first time and to help celebrate your daughters birthday. I can guarantee it will be magical no matter what you see or do.
You did not mention your daughter's age which is necessary to give you the best suggestions but I will give you some that would cover all birthdays for sweet little princesses. Please feel free to ask again and state the age your daughter will be turning.
Definitely arrange for a birthday dinner or meal and have a cake for her. You can get a cake the day of at any restaurant by just asking at the check-in podium or you can order a special designed one to be delivered to the restaurant. You will also want to look over all the special ideas that
Disney Floral and Gifts can arrange. They offer special birthday in room celebration packages which are pricey but they really are cute. The Disney magical fairies come into your room while you are in the park and decorate it so when you return your princess will be completely surprised.
There are tea parties and of course the
Bibbidi Bobbidi Boutique where she can be transformed from head to toe into a Disney princess. Reservations are required and if you can't get a date at the Magic Kingdom location try for the Disney Springs. Children must be 3 to be able to experience this.
Make sure you pick up a Happy Birthday button either at your resort or in the parks so your daughter can wear it proudly all day. Cast and guests will be wishing her a magical birthday the entire time. Disney also has some cute Birthday hats for sale you might consider.
No matter what I know you and your family will have a trip of a lifetime.