A Kentuckian may carry openly and legally a handgun or longarm at the age of 18 yrs of age.
A kentuckian may OWN said firearms at 18 years of age but may NOT purchase a handgun from a FFL holder until the age of 21.
1: You have already listed the laws.
2: Any legal weapon, loaded or not.
3: The factthere isno law AGAINST carrying at 18 literally means it is legal.