Light does not have a charge. "Charge" is just what we call the tendency of something to affect and be affected by electromagnetic fields, which are what light is made of. The reason positive and negative charges are attracted to each other is that they both give off these fields.

Is light a positive charge?

Photons have neither negative nor positive charge. They are not matter and have no mass. They travel the speed of light when in a vacuum like in outer space (which is not a complete vacuum, really). But they can travel much slower when traveling through a medium like water or even air.

What is negative about light?

When describing the propagation of light, the equations require that we describe the light field as having both positive and negative frequencies. A negative frequency would indicate a wave made up of photons that have a negative energy, something that doesn't necessarily make a lot of sense.