Hello and welcome to the forum!
There are many things to think about when acquiring a new pet. Things like how much money do you want to invest on set up/continuing care and how much time do you have for care.
Most people start with a Veiled Chameleon or a Panther Chameleon. Both have fairly easy care/cost requirements. Remember that if you choose a female that she will lay eggs whether she has bred or not(this isn't a bad thing, just requires one extra step in care). Although I would suggest you get a male as a first chameleon. If you like to handle your reptiles a lot, a cham may not be a good choice, as it's best to just not handle them, or only do so a couple times a week at most for only a few minutes. I really enjoy the simple interaction of misting a couple times a day and hand feeding.
Veileds can be a bit grumpy, but time and encouraging hand feeding can make them a bit more social. Panthers are a bit more laid back.
Here is a care sheet for Veiled Chameleons
https://www.chameleonforums.com/care/caresheets/veiled/
And a care sheet for Panther Chameleons
https://www.chameleonforums.com/care/caresheets/panther/
It is best to find a chameleon from a reputable breeder, instead of places like PetCo and the likes. Breeders will give you better info and will answer your questions even after the purchase.
Let us know if and when you are getting a chameleon. Post pictures too
