You don't need auto insurance if you don't have a vehicle. Even if you were driving your parents' or other family member's car, their insurance should cover you. Every lisenced driver in the household should be listed on their policy, even if they will never drive the vehicle.
You still need to have at least liability insurance. Other wise when you do get a vehicle, you will be considered as having a lapse in coverage which in turn makes you a risky client to insure and your premiums will be more. By keeping you on any family members policy will aleave you of this problem. And keep you from paying the higher prices.