“It’s so amazing that she’s so young and so successful. I’m worried about getting, like, one B, and she has this whole company thing that she’s doing and that she really enjoys. That sets the bar really high!†says 16-year-old Xulani Akel of Tavi Gevinson, who signs a copy of “Rookie Yearbook Two.†(Bethany Mollenkof / Los Angeles Times)