There are two things I would do. Bring most or all troops home, they are overseas helping other countries economies. Cut spending to go into research and defense of the borders and space agency.
With this money saved we could implement UHC, and save everyday Americans close to $6k per year. In which they could use to spend on the economy. That amount of aggregate demand (750 billion) would be the size of the stimulus but done every year by good old American citizens.