Well, if this is correct:
Light would be strong against normal (a normal person or animal that touch a light bulb, for example, it gets burned), water (the light can transgress the ocean), ice (things that produce light can burn and produce a hot weather, so theice can't be in front of a light bulb), fight (the same as normal I think), bug (just see what a magnifying glass can do to an ant...), ghost (because they are in the dark), dark (because if there's light the darkness disappear). It would be weak against grass (they use it to the photosynthesis), dark ( because if there's dark it's because the light isn't there). It would resist fire(because of the hot weather), steel (because it reflects the light). It wouldn't be inmune to anything.
But is your choice.
Light would be strong against normal (a normal person or animal that touch a light bulb, for example, it gets burned), water (the light can transgress the ocean), ice (things that produce light can burn and produce a hot weather, so theice can't be in front of a light bulb), fight (the same as normal I think), bug (just see what a magnifying glass can do to an ant...), ghost (because they are in the dark), dark (because if there's light the darkness disappear). It would be weak against grass (they use it to the photosynthesis), dark ( because if there's dark it's because the light isn't there). It would resist fire(because of the hot weather), steel (because it reflects the light). It wouldn't be inmune to anything.
But is your choice.