They could have started pushing social distancing measures earlier. Also, they might not be able to close airports on their own but if I am not mistaken screening and quarantining is something they could have started enforcing(or more strictly if they were already doing it).

Require masks in enclosed public places.

No but the Feds have already shipped supplies, built hospitals and closed travel to China & Europe.

NYC has the economy of some small countries and they do have the backing of the Fed, no matter what excuses Cuomo gives.