How old are you? 24-25 or somthing? Cali is very very expensive to live. How's your education? got a degree?
To me... it sounds like your fiance Is deciding to move here to cali without much concerns for your well being. but.. your son needs you and it's good you've put him first. This is a pretty big decision, hopefully you can figure out what your employment options are and try to see if cali would be a comfortable place for you and your wife/kid to live.
Cali's great! if you can afford it. lots of oppurtunities, and things to do.