He seems to have accepted everything already, though, what with him catching a pokémon and whatnot. If I'd been him I'd still be at the professor's, asking questions and staring in fear at all these strange, alien concepts. I certainly wouldn't leave the one person who's most likely to have immediate answers - a pokémon professor. But that might just be me.As I said earlier, Red will realize that Tanko is a glitchy version of Kanto, and very soon, too. Once he starts to work past the fact that he's in an alternate dimension where everything is all glitchy and people grow numbers in their gardens, anyway.
Fair enough on Redwood maybe not wanting him to go yet - which seems odd, especially since he was the one mentioning that Red needed to go to Bincanar Island, but fine - but surely Red would realize that there'd be other ways of getting there? He's stranded in an unknown world. I'm sure he'd like to get back to his own as soon as possible. And even if he didn't realize that, the other two kids would probably know there are, logically speaking, other methods of transportation to get there.As for why Redwood didn't try any other methods of getting Red to Bincanar Island, he has his own reason for wanting Red to travel around Tanko, which will be detailed later in the story.