At the start, on the page you see now, you need to press the up arrow. From then on, you are asked your name, answer with prefix only. Then just answer the questions. You start out as a kit, then you become a 'paw, then a warrior, deputy and then leader! I must warn you though, if you can't guess the last question, you are thrown out of the Clan and become a rogue. Good luck and may StarClan lighten your path!
All the credit goes to Erin Hunter who writes the warrior cat series. I've read the following: The prophecies begin The new prophecy Power of three Omen of the stars A vision of shadows If you haven't read any of above then I'm sorry to say that you'll find this quite difficult.
