Question about Twallan's story driver

How do I go about making my sim part of the Slayer clan? And if I do join the Slayer clan, will I get to slay evil vampires? I found the leader of the slayer clan at a pool and I chose "ask to join" but I didn't see any sign of my sim being in the Slayer clan, and the menus are a bit confusing.

Edit: I am starting over, but what traits does a sim need to be a protoge of the town robin? I guess that klepto and good are two of them, maybe charismatic, but not sure about the other 2.

I assume you're talking about Story Progression?

I don't have the Vampires and Slayers module installed, so I don't have any answers for you but you may find some useful information here.
http://nraas.wikispaces.com/StoryProgression+FAQ

If you still have questions, the best thing to do would be making an account on Twallan's wiki and asking there.