OP, your dad has a good point. If you can't regulate humidity extremely precisely WITH a screen cage (since chameleons basically can't live in glass terrariums) then the chameleon will die. Period. That screen cage will need to be huge by the way if you're keeping a veiled, about 100 gallons. These enclosures are difficult to find and can go for over 600 dollars. Temperature will also have to be kept within a range of 1-2 degrees fahrenheit. They also hate being handled and will bite if they are. They bite surprisingly hard, and large ones can more than draw blood. If you handle them too long, they will literally die of the stress. Are you a new reptile keeper? Because if you are, you have almost a 0% chance of being able to take care of a chameleon.
Chameleons are specialty display animals that require a lot of experience with reptiles, about $1000 total for a full setup, and a huge commitment to care throughout their long lives. That doesn't mean they're not rewarding or are not worthwhile to keep. It just means you need a lot of money, a lot of time, and a lot of experience to take care of them. They also have a tendency to drop dead for no reason even if you take care of them perfectly (ask anyone who's kept chameleons about this). If you are considering your first reptile, I would recommend a fire skink. They can be kept in pairs, are large (up to 15 inches), don't require a lot of space (45 to 75 gallons for a pair), and are super fun and rewarding to keep. They have an amazing feeding response and are not at all averse to handling. If you're dead set on a chameleon, get some experience with other reptiles first, because I can almost guarantee your chameleon will die if it is your first reptile.
Give it some more thought, and go ahead with it if you like. It's your pet and your money. Just know that I would not recommend it at all.
*before you ask, yes I have chameleons
