No. The Supremacy Clause (Art. VI, Cl. 2) makes federal law the supreme law of the land. The text of the clause is: "This Constitution, and the Laws of the United States which shall be made in...
Federal laws are the Supreme laws of the land. If there is a conflict between the two, Federal law prevails. State laws may be in addition to Federal laws, such as for some crimes a person may be...
Not quite... federal law is federal law and is in addition to state law, except where there is a state and federal law that are virtually identical, in which case the federal law may "supersede" the...