Qualifications
There are no absolute qualifications for becoming a choreographer. It's possible that you were born talented, that you can effortlessly blow away the studio hacks who studied for years, that you can revolutionize the dance world with your raw, mind-blistering genius. It's also possible that pigs will fly.
Pretty much every choreographer started out as a dancer and has studied the art form long and hard. Many start when they're tiny tots at local studios, and then work their way into professional studios and and/or college programs. High profile programs like the ones at Julliard or NYU Tisch can give you a huge leg up professionally, but there also a ton of other great dance programs out there with various specialties (source).