If you're confident in your stand-up, start learning some sort of ground skills (wrestling, BJJ, judo), without a ground game you won't go far.
When you're confident, head to an MMA gym, they can make sure you're ready, and point you towards some amateur fights. If you do well in those, you could get picked up by a small pro fight league. If you're REALLY lucky / talented, you stand a small chance of getting scouted by the UFC.
It's really not something anyone can tell you how to do, thousands of fighters are considered and turned down just for TUF, let alone an actual UFC contract.
D. Cerrone | R. Souza | F. Werdum | R. MacDonald | M. McDonald | D. Maia | J. Mein | C. Condit
M. Coenen | S. Kaufman | A. Davis