How does the junior toy hunt work?

I just got the junior toy hunt, there are 9pieces x 6toy custumes = 54 pieces total, and 29 days to collect them meaning I must average 1.86 unique pieces daily to get all 54 before the end of the challenge.

But I don't know how to earn pieces to start with. I got 2 pieces from 3 lessons, and it seems like I'm not getting any more, no idea what I need to do to keep on earning them without resorting to spending gems