Sunfall will eventually come where Crystalblaze used to always be, and he will ask you to come say hi to his sister
Next, Garble (the mean guard--but LOVE HIM MOSSS-SHADOW!!) will let you in. Talk with the cats as far as you can go, ask them about Crystalblaze and Sunfall, and she will tell you where they are.
(They will be backstage in the tent, but you can't get in without talking to them first)
Chat with Crystalblaze, and you can always come back to the fair, and Garble lets you!
You can also go the black she-cat who helped you before and join the fair cats.
NOTE: YOU CANNOT COME BACK TO THE CLANS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
If you do join them, things to do are limited, as well as what the NPCs (non-player-characters) have to say. BUT Sunfall will let you switch your name.
HOPE THIS HELPS!