You can give a quick check (or sniff) around the car to see where the smell of gasoline is strongest. Then with the car idling, check under the car for signs of dripping fuel.

If the smell is coming from the engine bay, check along the fuel line and the engine itself. Among other places, check the sparkplugs if they are wet.

Check if fuel is leaking from the hoses and metal fuel lines. Ethanol in E10 gasoline can erode metal fuel lines and also prematurely harden rubber fuel hoses.