As far as we know, there's no such thing as magnetic charges (not like there are electric charges). This is because magnetic fields are due to the movement of electric charges as an effect of relativity. In fact originally relativity came from studying the interaction between magnetic and electric fields. Basically the best way to think about it is that all magnetic fields come from the movement of electric charges; and as soon as they stop moving, there are no magnetic fields (so there are no magnetic charges).

I don't know what you mean by "charges". Light is an alternating series of waves of electric and magnetic field, where the two fields are ninety degrees out of phase. The strength of the fields ('amplitude') is the intensity of the light, and the alternation speed is the frequency. The energy of the light is the product of the amplitude and the frequency.