The trainers got off a boat called the S.S. Bolt, and then gathered in front of a timid scientist, who gave them a rather lame tour of the corinthian style architectured city. He also pointed out a plaza with a fountain where they could get supplies. They then arrived at a rather featureless lab where the professor greeted them, went to grab the pokeballs, came back, and had everyone line up. Now they're getting their pokemon

That's the short version.