Being a loan officer could make you quite a bit of money, if you are good at it. Meaning, you are good with people, and building relationships, and of course...cold calling. If you can stay away from a job that requires you to cold call for more than 80% of the time.
Also, try and find a place which offers a base salary as well as commission, not just commission. As far as certifications go, it varies state to state, I'm not sure what the status is of CA.
Going to school to be a loan officer is not necessary, but most companies love a business major, and if you have sales experience, that could trump your lack of a degree.