1. Refuel: Add gasoline to the tank. This seems obvious, but it's the crucial first step. Make sure you're using the correct type of gasoline (check your owner's manual if unsure).
2. Start the Engine: Once you've added enough gas, try starting the engine as you normally would. Sometimes, after running completely out of fuel, the fuel pump may need a few seconds to prime itself. If it doesn't start immediately, try again after a short wait.
If it still doesn't start after refueling, there might be a secondary problem unrelated to the lack of fuel. This could include a dead battery (from repeated attempts to start), a faulty fuel pump, or another electrical issue.