In other words, states have a lot of latitude to make whatever laws they want, unless a federal law specifically prohibits it?
The major difference is the Tenth Amendment, which sets the states apart by specifying that any powers not "delegated to" the federal government are reserved exclusively for the states. (In practice courts have found many "implied powers" that are not explicitly enumerated).
Federal laws are distinct from the Constitution.
The Constitution, its Amendments, and decisions of the Supreme Court are not 'federal laws'.