Do you like watching the dance? Have you ever wished you could dance it? If the answer is yes, I think you have enough interest to carry you through the learning process.
I was in the same predicament a year and a half ago but just like what Twinkle said dive in there and practice, practice, and practice. At your stage, there is nothing to lose, everything to gain. People in this board are very helpful along the way. BTW, waltz is now my favorite. Good luck. 