If you are a registered organ donor will your family have first dibs on your organs if they need them?

Yes. In some states, donors and donor families may specify who can receive cadaver organs. If you have a friend or family member who specifically needs an organ, your wishes can give them priority over those in the general waiting pool.
Possibly. If you are a registered organ donor you can direct your next of kin to your wishes regarding organ donation. However, that would assume you already have a family member with end organ disease, and that you would be a suitable donor. Those are situations that are not easy to predict in advance.