The judge likes to see some form or enrichment in the carrier / travel cage he is in. This can be something like a cardboard tube or box, a nibble stick or a wooden chew. Bedding should be safe (not fluffy) and absorbent and there must be a source of food and fluid. This can be normal food or a dog biscuit and for fluid a chunk of veg like cucumber or a mouse water bottle.
When I judge pets I like easy access to the hammie so no small tubes or tiny enclosed boxes he can wedge himself in. I personally prefer a safe carrier or a smaller sized plastic tub with ventilation as these are easy to get the hammy out of.
I would say 6 weeks is really rather young for this sort of experience. Part of the judging is on tameness and they can go a little skitty when they move home and if you have only had him a week he may still be settling in. You can decide the day before the show though - that's the beauty of pets
Young stock is 9 -16 weeks so I think he would be too young at 6 weeks to go in main show myself but you could check with the show sec on that as it may vary club to club.