To be a princess in your own fairy tale you need to have that one special dress - all the princess have it! In "Beauty and the Beast" Belle has a huge, yellow dress, Cinderella has- now called Hologram colour- dress and Rapunzel, on the other hand, have a pink dress as I do! 

So to enjoy your love story you need to choose dress first. I always suggest EverPretty because they have a large assortment and dresses for everyone's taste.