I got beaten but it put me back outside. There is a guy there that says " My apologies, young trainer. But you may not enter the Pokémon league at this time." How do I get back in to fight him again?
Go to the little building next to him, where the pokecenter and shop are, and there should be a Team Plasma guy standing there. Talk to him and you'll warp back into N's castle and can try again.
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