This is the easiest topic. All you need to know is what that fangirl/fanboy's fandom. Normally, you can find them anywhere. Your cat may even be in a "squishy toys fan club". You will never know. It may have secret tiny photos of she-cats under their little beds.
Okay, getting back to the topic.
As I said, you can find them anywhere.(The fangirls and fanboys, not the fancats) But there are some places where you can find a lot of them(Or just their hideout). Here's the list:
•Bookstores
•CD stores
•Concerts (duh)
•Your school
•Author conventions or signing of books
WELL I'M RUNNING OUT OF IDEAS.
And some odd places like:
•Under their bed or blankets in the middle of the night
•In the corner of a dark room
•Under your sofa
•Arguing with the guard at the Empire State Building
•-Dead-
The last one was not meant to be there.
P.S.: Don't trust this guide anymore