If you are in a car traveling at the speed of light and you turn the headlights on, does anything happen?
First of all, “does anything happen” is pretty relative. So I’ll take a poke at what you intended to say.
According to Special Theory of Relativity, if you’re traveling at the speed of light you would have NO headlights: the whole car and you would have turned into pure energy (photons of light ) and you would be one with the universe. But if you are traveling very close to the speed of light, the light from the headlights will still appear to go forward at the speed of light relative to the car.
Hope this helps. Enjoy your trip 😉