According to the tenth amendment i have more authority to determine a laws constitutionality than the supreme court does. THINK
According to the 10th amendment, states can only make laws that aren't in conflict with federal law.
Correct.
Supremacy Clause | LII / Legal Information Institute.
However, to take that definition at face value is not simple.
As with any law, there is always room for interpretation and even challenge.
Just because the Supremacy Clause exists, does not mean a State can make law that challenges federal authority. In other words, a carefully worded law can be legally enacted and appear on the surface that it may be in conflict with federal law, but is actually not.
For example, The Federal Wire Act of 1961 prohibited the use of communication wire lines to place wagers of any kind. The fact that betting on horse racing via the internet is legal in states where Pari-Mutuel wagering is legal in the state from where the bet is sent to the state taking the bet is evident in that the Act did not address specifically the wagering on horse racing. Essentially the Act covered wagering on "sporting contests".
Also. the Wire Act specifically mentions "common carriers". As of the present, internet service providers are NOT considered "common carriers".
Sen John Kyl (R-AZ) introduced a bill that would make ALL internet wagering of any kind ILLEGAL in the United States. That bill did not make it past committee.
The point here is where the US federal government can make law which then subjects that law to the supremacy clause, in certain instances such a law is open to interpretation.