So Cal Land for Investing or Sell?

[Al Kim]

My parents have a 20000 flat lot with a small SFR in fair condition on RD1.5 zoning in Los Angeles county, suitable to build a 10-16 unit apartment or subdivide to attached/detached condos. The property is adjacent to 10-unit (10000sf lot) and 20-unit apartments (20000sf lot) and backs to newly developed townhomes. It has a mortgage of 400K remaining and the value of home per zillow is $600K but the land value I could sell to investors for over $1mil. I wanted to invest my parents' property but construction loan might be impossible for me as it requires capital and time invested. I'm currently in doubt if I should just sell as vacant land to investors or should I seek to invest myself into building an apartment and rent it out? I would like to know if anyone had a similar experience or any ideas how should I deal with my parents' house.

I got excellent credit, no debts, I own a home and steady job in real estate market.

In the other perspective, I'm currently working on real estate business but never started to invest properties. I would like to start investing in some rental properties where the demand is great, although I know Southern California on palm of my hands but I would rather start elsewhere like Texas or Las Vegas Nevada if market is great, California is way over the market and I think I might not afford at this time. 

I am new to investing real estate but I have been working on real estate business for half of my life. I have been starting to listening to BiggerPockets podcast today, I look forward to learn great advice from here, thanks in advance!