You are correct. Johto isn't located on Auldrant. It's located in another world entirely from your own, so no one will be able to tell you how you can reach any of the places you asked about. As for how you came to be here, no one's discovered the answer to that question yet. We're all flying blind on that matter.

[ And she pauses, taking a moment to slap the hand of the Cyndaquil hanging off her shoulder. He was reaching to cover one of her eyes and she didn't appreciate that very much. ]

If you're looking for lodgings, you'll find them in Cherrygrove City. It's the next town over and it's a three day journey, if you're traveling steadily. If you've got any other questions, I'd be happy to answer them for you.