We need more information...what species?
What are the temperatures in the cage?
Is the food and appropriate size? (for example crickets should be a good size to fit in the mouth comfortably.)
I have a Veiled chameleon Gender (I dont know), humidity 70, basking spot 30C, day cool area 25C
Tried small crickets and big crickets and mealworms and waxworms.
You just got him yesterday; he's acclimating to his new environment. It's not uncommon for them not to eat anything for up to a week or two when you first get them. Just make sure he stays hydrated.
not uncommon for them not eat when shedding and when there's been a lot of change (moved to new cage)
if its small, don't let the temps be too high. keep range within 70-80F/21 -26C if its younger than adult.
provide water in the proper way (spray, drip)
give it some days to settle into the new environment (don't watch it all the time)
offer appropriately sized food