I'm busy tomorrow as well, as it turns out. I'm on personal business in Cianwood City. [Hence the obvious hotel room in his background.] I'll see what day I make it back to Goldenrod, and we can organise something then. You should only be training for around a week, so soon you'll have a lot of free time.

According to what I've read on them, they're not a native Pokemon to Johto or Kanto, so they're extremely rare. There's rumours of them being found in the Ruins of Alph - a set of ancient ruins located quite close to Violet City, it's about a five-day hike from Goldenrod - but they're allegedly quite rare.