I am asking this because a Bank I contacted told me that they won't typically work with someone who does not have any prior experience building  multifamily and suggested that I consider purchasing an existing property instead.How else would you gain experience?

I am not you and you are not me, we live and invest in different markets, we have different goals, we have different skills, and are in different financial positions ... our return expectations therefore are and should be different.

My goal with real estate investing is to build enough cash flow to fund my other business ventures as well as donate to financial literacy programs.  

I met with the tenants two weeks prior to end of lease. 

My question is this: if your goal is to create at least $20k in net monthly cash flow in 8 years, and you have $300k to get started, how would you invest that money?

We would then use that 20k as a down payment FHA on a multifamily, house hack one unit, rent out the other three, and rent out the condo.Based on prior estimates from a RE agent, we could rent our condo for anywhere from 1.3k to 1.5k a month. 

THAT was a huge learning experience and led me to reevaluate my goals.

You would need to look at your age and if doing estate type planning or general investing with the goal at some point to 1031 exchange into something else as a strategy.

@Liz Boer I think if you're looking at San Diego's viability it mostly goes back to your goals.  

Keep positive outlook and visualize your goals and take action.