Hi Jessica:
During the Year(s) of a Million Dreams promotion, guests were randomly selected to spend a night in Cinderella's Royal Castle. That promotion has expired, and this year's promotion is "
Let the Memories Begin." As of now, the suite in Cinderella's Castle at Magic Kingdom is not available for booking by guests, nor is it generally randomly given to guests for a night's stay. I imagine certain A-list celebrities may have a shot of booking the castle, but for the rest of us, the suite is not an option.
From time-to-time, an overnight stay at the Castle may be offered for charity purposes or certain promotions. However, there is nothing I can tell you to do to be selected for any of these promotions, to the extent they are offered.
You may want to consider a stay at the
Grand Floridian Resort and Spa, considered by many to be Disney World's most magnificent, luxurious, and picturesque Resort.
Enjoy your vacation.