At petsmart they sell 1 in a box ( Hornworms) and its usually dead or has already begun turning into a moth, so i would just forget about petsmart all together, order online and get a 25 count cup.
A shoe box with a towel inside and possibly a small branch for it to cling to but I would make sure the vet is trained in reptiles, I've heard of some vets just don't understand reptiles and can possibly do more harm than good but seeing a vet is the first step and good for you for taking it...
If it doesn't see a vet, then yes, it possibly needs calcium injections or liquid calcium the vet can provide. At this point there's nothing really you can do to fix the problem. Like I said before you're at a crossroad and I'm so sorry but the good thing, it's at a point that you can save it...
Which is why it's in bad shape, it's pulling calcium from the bones to use it for the major organs, if you are not gutloading it's food, crickets or other feeder it doesn't matter if it's eating because most feeders are high in phosphorus which is why you gutload the feeder to make them more...
It depends, you need to get your parents involved or have them look at some of the threads but if this isn't taken care of it will die a slow painful death, you or your parents need to contact a vet.
I would stop handling immediately just so no bones get broken, put a branch lower with a towel underneath so if it falls it will be cushioned. It's in bad shape but it can be helped if you can get it to a vet ASAP!
Have you contacted a vet yet, those pics with the limbs just doesn't look good, looks like early stages of MBD if it is MBD and doesn't get meds soon you're going to have a empty cage. You're going to find out how expensive Chameleon are. Best of luck.
Your Veiled doesn't look to be in good shape, I'd find a vet and take her to them asap, find a reptile specialist. Wait to long and you'll be at the point of no return.
No heat lamp is needed at night, a drop in temperature is actually a good thing, you need way more plants in your set up so it can hide and not be stressed, which he/she is going to out grow quickly. You need to look at the care sheet for Veiled chamelons! The care sheet will tell you what...
The cham is in bad shape, you need to take it to a vet ASAP! Where did you purchase it from? It looks dehydrated and definitely some type of eye problems, do you gutload your crickets and giving them hydration? A pic of your set up would be helpful! You need to fill out the Help Form.
Sometimes they just get bored if you are only using one or two feeders over and over, try hornworms, superworms, butterworms, crickets, dubia roaches, black soldier fly larvae. Try to get a variety of feeders, plus it's great for your cham!