In time, after your curiosity has been satisfied and you get immersed deep into the practice, you will be convinced that yoga is good for you in more ways than you think. It will be more meaningful and, most importantly, personal.
Yoga starts with meditation. It can be a quiet meditative pose or it can be mantra-driven. A yogi/yogini is a person who practices yoga. It doesn’t require any sort of graduation or promotion ceremony to become a yogi. It comes from mastering the practice, discipline, and philosophy of yoga.