For starters, the correct stance you should start with and correlate to if you are right-handed or left-handed. If you are right-handed or orthodox, you should start and practice that stance first. If you are left-handed or south paw, you should practice from that stance first.
Having a proper base and stance and a strong core will help punches flow from your natural stance. Once you master good footwork and throwing punches from your natural stance, you can go to the next level and learn how to fight and switch up from one Stance to the other. (Switch for orthodox to south paw, and vice versa) This is not easy to do, but over time it can take you to your next level of fighting!