Until you have time to answer the questions in the how to ask for help thread at the top of the health forum here is some information to get you started...
Its recommended that there should be no lights on the cage at night unless the temperature drops below 60F.
The long linear Repti-sun 5.0 tube light is the most often recommended UVB light. Exposure to UVB light allows the chameleon to produce the D3 it needs to be able to use the calcium in its system. D3 from supplements can build up in the system and lead to health issues but as long as the chameleon can move in and out of the UVB at will there should be no problem with D3 building up from exposure to the UVB.
Since most feeder insects have a poor ratio of calcium to phos. its important to dust with a phos.-free calcium powder at most feedings. The dusting is done just before the insects are fed to the chameleon.
Twice a month its recommended that you dust with a phos.-free calcium/D3 powder to ensure that the chameleon gets some D3 without overdosing it.
Twice a month its recommended that you dust with a vitamin powder that has a beta carotene (prOformed) source of vitamin A. PrOformed sources don't build up in the system like prEformed sources do so this leaves it up to you to decide when/if the chameleon needs some prEformed vitamin A.
Its important to feed/gutload the insects well. Crickets, roaches, locusts, superworms can be fed/gutloaded with a wide assortment of greens such as collards, dandelions, kale, endive, escarole, mustard greens, etc. and veggies such as carrots, sweet red pepper, sweet potato, squash, zucchini, etc.
With proper UVB light, appropriate supplements and feeding/gutloading of the insects and appropriate basking temperatures that will allow the chameleon to digest its food well (thus absorb nutrients well) you have the best chance of your chameleon being healthy.
Also be aware that some egglaying chameleons can produce eggs without having mated so its important that they have a place in the cage to dig to show you when they are ready. Failure to do so can lead to eggbinding.