These meetings happen about once every ten days. Outside of that, people have their own schedules, so it depends on how committed they are.

[Shun trains pretty much every day if he can get away with it, just varying what in particular he's training and who he might be doing it with. But he doesn't really know anyone else's training schedules in depth, so it's not like he can talk about it with too much expertise.]

If you're worried about how long it'll take to figure out that power, nobody's going to care if you spend more time practicing until you get it.