Congratulations! Dancing is a great thing to focus on. (Just don't let it become more important than family or school.)
Practicing a lot is the best thing you can do.
But you can also learn about dancing in other ways:
watch good dancing whenever you get a chance (TV shows like "Dancing with the Stars" and "So You Think You Can Dance", ballroom/latin dance videos on YouTube, check accessdance.com for any ballroom competitions in your area so you can go and watch)
check with dance studios and college ballroom teams to see if they have practice dances that are open to the public. You'll probably want to get a group of your teammembers to go to these dances together, because especially at the studios, most of the other people will be older.
learn about the history of ballroom dancing (websites, books, etc.)
if you like crafts, you can start learning some dance-related crafts, like sewing and applying rhinestones. If you get serious about dance and decide to compete, you can save a lot of money by making some of your own costumes or buying plain dresses and adding your own rhinestones. A good resource is rhinestoneguy.com.
Enjoy!
