Hello BiggerPockets Crew!

My name is Vincent, I am new to the forums. I was hoping I could get some advice/guidance on the below questions from you guys. 

My overall goal is to get started in real estate investing in small rental properties (duplex, triplex, etc.). I realize SoCal is not the most ideal area to invest in rental properties, but I plan to live in my first property. I have an idea of what I need to do but would like to hear from all of you.

1. I currently bank with a credit union, is that a good option to apply for a mortgage loan or should I branch out? If so, any recommendations?

2. Any recommendations on local real estate agents/firms that could help with my search?

3. I want to get myself into a triplex or fourplex, but I'm noticing these are hard to come by. Is a duplex a bad idea?

I appreciate any advice you guys have to offer!