Maddie, I don't mean to be rude, but you are asking a lot of really basic questions. It makes me worry that you are not quite prepared. Chameleons are very high maintenance animals - far more than other reptiles. It may cost you a few hundred pounds getting all the equipment and supplies together. Plus you need to have a veterinarian that specializes in chameleons and a fund for vet costs which can get very expensive. Lights, supplements, misting systems, insects... It adds us quickly.
Have you read through all the general care information on the forum? If you go to the main page of chameleon forums, at the right side is a box called "Start Here". There is all the basic information you need to get started. There isn't a care sheet for carpet chams, but if you do some searching, I sure someone here has specific advice.
I just don't want your to get in over your head. Chameleons are fantastic, really special animals, but they are a " lookin but don't touch " animal for the most part and can be rather delicate in health.