As a matter of law the federal government controls the international borders and inter-state boarders. It is up to the state governments to limit movement within their borders. https://www.cdc.gov/quarantine/aboutlawsregulationsquarantin...

As it so happens, President trump has been limiting international travel starting all the way back in January.

Why do you think the federal government isn't "doing much" (https://www.usa.gov/coronavirus)?

And what exactly would you have it do that you don't think it is doing?