The National Firearms Act, Gun Control Act and other laws have been ratified by Congress to support the right to have arms, which is a human right according to the U.S. Constitution. However, penalities for carrying a gun with no license are dependent on several factors.
Different State Laws
Each state controls their own firearm legislation. In Arizona for example you can carry a concealed gun without a permit but in Michigan you will need to be over 21 and have a permit. Therefore the consequences of being caught without a license or permit will depend on where you live.