Don't plan on housing them together. They are not eating for several reasons. Chams who have been sent to a show are really stressed and would probably only eat out of desperation that first day. They are in a completely new space, surrounded by strange people, sights, each other, etc. They have traveled, been crowded, exposed to temp and humidity changes, odd lighting, everything is overwhelming them. Don't assume the breeder kept the pair together all the time. If he did, it was probably not the best idea unless he had a greenhouse sized enclosure.
Separate them as soon as you can. Set up their permanent cages and leave the whole setup alone once the chams are in them. Don't spy on them too often, but provide dripping or sprayed water, correct light and temps, a lot of plant cover, and not too many feeder insects at a time. A stressed cham can be overwhelmed by the sight of too much motion and not shoot at anything.