I show my discus at regional fish shows in the US and here's what I do.
1. I don't isolate my fish, although I know many people do. I find fish that get daily water changes don't get spooked at shows.
2. I use a plastic colander to move the fish from the tank into a bucket for transportation. In the US, we can get 5-gallon plastic buckets from Home Depot for $4, including lid.
3. I stop feeding my discus 48 hours before moving them so they don't poop in the show tank. A hungry fish is also more lively.
4. I use pure R/O water to transport my fish to avoid any fin burn from accumulated ammonia. If possible, I bring extra R/O for the show tank.
5. I keep extra sponge filters cycled in my grow out tank. This will immediately cycle your show tank.
6. Make sure there's a heater and a light available at the show. If the show doesn't supply them, plan to bring your own.
7. I always have a tight fitting top for my show tanks. There's going to be splashing from adjacent tanks, so have a quarantine tank ready when you come back.
8. I like keeping show discus in 10-gal tanks. It may be a little cramped (I have 7"+ fish), but the discus really look huge!
People who do well at shows usually did some preparation beforehand. It's a ton of fun, so enjoy!
Willie