why does photon travel at the speed of light if theoretically nothing could?

a "photon" is an electromagnetic wave. All electromagnetic waves, including light waves, travel at the speed of light. Nothing with mass can accelerate from zero to the speed of light is what you are thinking about. The word 'photon' gives the impression that it is a particle, but it is really a 'quanta' of energy.

Light is made of photons, and the speed of light is the fastest speed in the universe. Since all other factors of dimension, including space and time, are dependent on the speed of light, that means the speed of light is a constant, "c" and never changes. Since the speed of light is theoretically the fastes speed anything could ever travel in 3-dimensional space, nothing else could reach that speed (just like nothing can ever reach absolute 0 temperature, since it's the lowest theoretical temperature)

I think you answered your own question.

Theoretically, only a photon can travel at the speed of light.

Photon is the packet of light waves and thus you can think of it as a particle. It will cease to exist if it doesn't move.

Yes, it is able to travel at light speed because it has zero rest mass.

Fundamently, the collapsing electric field pushes the magnetic field which then collapses to push the electric field. In the process the fields propagate foward at a rate determined by the way freespace allows them to rise and fall. The speed of light is a fundamental property of space.

The photon is just the quantum of light, and c is the speed at which it propagates in free space. And yes, if you consider it or treat it as a particle, it has zero rest mass.

Photon is nothing but quanta of light. what you told is correct.
the light (photon) travel in the speed of C. Still what is meant by cloud. Cloud do nothing. May be reflect the light