Find the gems, move the cave stone, get a prophecy. Train till 300 health, go to FireClan, kill Firestar. Make Breezesong leader of FireClan, and agree to meet her at night. Talk to her often until she says she thinks Ryeheart is your father, you have to say yes to her. Then she'll let you go into FireClan. Talk to the FireClan cats to find out about the gravestones, and decorate them with flowers.