Light travels 300,000 km per second.
It travels 15 km in (15 / 300,000) = 5 x 10-5 = 0.00005 second
(0.005 millisecond, 50 microseconds)
The answer is neither.
It would turn to energy
No. First of all you could not. But if you could, then time would stand still, not backwards.
Sunlight takes 8.4 minutes to travel 93 million miles to Earth. It would take us that long to reach the Sun at light speed.
The only way to travel at the speed of light is to not have any mass.
Objectively, about 26,000 years - but IF (and you cannot!) you could travel at the speed of light, it would seem like no time at all had passed.
The Milky Way galaxy is about 100,000 light-years in diameter. If you could travel at the speed of light, it would take approximately 100,000 years to cross from one side of the galaxy to the other. However, this is a theoretical scenario, as current laws of physics suggest that nothing with mass can achieve the speed of light.
Light cannot travel faster than the speed of light, so a bulb traveling at the speed of light is not possible in the laws of physics as we know them. If it were somehow possible, the bulb may emit light, but we cannot definitively predict what would happen under such extreme conditions.
It would take approximately 65 years to travel at the speed of light from Earth to Aldebaran, which is about 65 light-years away. However, currently, we do not have the technology to travel at the speed of light.
No. Just to travel AT the speed of light would require more energy than the entire universe contains. So all objects move at some fraction of light speed, never 1 nor greater.
In the furthest reaches of the Solar System is the Oort Cloud; a theorized cloud of icy objects that could orbit the Sun to a distance of 100,000 astronomical units, or 1.87 light-years away. Therefor at the speed of light it would take about 3.74 years to travel the diameter of the Solar System. However no object with mass can travel at the speed of light.
you would never get old, but you wouldn't be able to see yourself