According to Witchvox there are no teen covens in Las Vegas. You can see all the listings for Nevada at http://www.witchvox.com/vn/hm/usnv.html
As for adult covens, you're unlikely to find a reputable group that would accept you without permission from your parents as teaching Wicca to minors without that permission is against the law.
Running a coven is a lot of very hard work. It's a lot more than leading the occasional ritual. You also need to be adept at group dynamics, teaching, counseling, and more. What you might find easier at this point in your path is to form a study group where the whole object for the group is to get together to study more about coven work and Wicca but where no one has to be the one in charge...and the one to blame if things go wrong. And I'd highly recommend the books "Covencraft" by Amber K and "Wicca Covens" by Judy Harrow to help you gain the skills to eventually form and run a coven.
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