Is there a self defense law North Carolina?

Yes, there are several laws. North Carolina has a castle law which removes the duty to retreat before using lethal force in your own home or vehicle. Other than that, the duty to retreat does exist. You may not use lethal force against simple (unarmed) assault, you may not use lethal force in a situation which you provoked, you may only use lethal force in third party intervention when intervening on behalf of a party which would themselves have a legal right to self defence as defined under NC law. You may not use lethal force to protect property.

I'd recommend you take the concealed carry class for better understanding of these laws. If you live in the Triangle, and are already familiar with firearms, I would recommend the course given by Charles Lett in Holly Springs.