How do i start if i have never exercised?

Start slow: The biggest hurdle is just starting. Start with walking 15 or 20 min 5 days a week. Increase the time to 30 min after a few weeks, then after a few more increase to 30 min 6 or 7 days a week. Make exercise become a habit, then worry about intensity or new types of exercises. The biggest hurdle most people need to overcome is just getting off the couch.