Fossil fuel reduction in the US is an engineering problem — build out more renewable power and nuclear, make the grid more robust. Electric cars for shorter trips by land, frequent and relatively fast (not TGV speed) electric trains for 200-750 mile trips by land. Highly automated car rental available at endpoints.
Encouragement of energy conservation. It won’t kill anyone to use LEDs, have lights on motion sensors, or dry clothing on a rope vs a dryer. Nor to heat to 68 in winter, cool to 75 in summer.
Who pays for it? We will, via taxes on fossil fuels used as fuels vs for chemical processes.