How do you get into a catching show in Pokemon SoulSilver?

You can't actually get into a Catching Show in Pokemon SoulSilver. There is no such event or minigame in the game.

However, there are some events related to catching Pokemon:

* The Bug Catching Contest: This takes place in the Bug Catching Contest Area in Goldenrod City. You compete against other trainers in catching and battling bugs.

* The Pokéathlon: This is a series of minigames that test your Pokémon's various skills, including catching. You can participate in the Pokéathlon at the Pokéathlon Dome in Ever Grande City.

Perhaps you're thinking of a different Pokemon game? If you can provide more context, I may be able to assist you further.