Ok the baby will not last long like that. He is shutting down and he is underweight. We can help you with questions on changes. The lighting is the upmost importance right now and a reptile vet that knows how to treat chameleons. Remove everything in there and get a nice umbrella umbrella plant to fit in that enclosure. This will give you the height you need. Leave the top 9 inches of the cage clear or when you get the new T5HO and 5.0 bulb you can raise it up off the top of the enclosure. You want 9 inches from the highest point baby can get to and the bottom of the new fixture.
Understanding the basics from that website is going to teach you far more then we can in a short period of time.
