Awesome of you to join us Cassy! Like Chaeli said, the flexibility in starting is all yours. What I did in my character creation was tie my character's death to an actual playing PC. That gave me someone to go after for vengeance, as well as someone to thread with in a PC to PC capacity.
Also like Chaeli mentioned, it's good to have some good, big, gripping goals as a Ghost. The thing about being a Ghost is it's very easy to not be a Ghost anymore. A moment of weakness where you repent for your Ghostliness will just about send you back to the cycle. Knowing that, you really need to have something to hold on to. It could be many things because after you complete your task, if you only had one, you wouldn't really have much reason to continue in the existence of a Ghost.