Here's what you need to do to become an apprentice:
1) Have been a member on this site for a quarter moon (one week).
2) Have posted in at least one topic in the forest (not including your cat creation and Clan selection).
3) Have created a cat in the cat creation and gotten it approved.
4) Have selected a Clan and gotten it approved.
When you have met all of these requirements, please pm your Clan leader and tell him/her that you have. They will hold your ceremony when they are ready.
P.S. At the moment, I have taken over all leader and some apprentice training duties. So please pm me if you have met the requirements. Read this for more information.