For starter, I am married to my 9-5 job and looking for a way out.

Good job 4's are the way to go! 

Skip the class and go straight to learning on the job.

Also, focus on 2 years of job/income stability.Class D Properties:Cashflow vs Appreciation: Typically, all cashflow with little, maybe even negative, relative rent & value appreciationVacancy Est: 20%+ should be used to cover nonpayment, evictions & damages.Tenant Pool: majority will have FICO scores under 560 (almost 30% probability of default), little to no good tradelines, lots of collections & chargeoffs, recent evictions.

My main goal is it be able to retire at age 40 from my main job and work entirely on my real estate portfolio.

You have to allow time to do its job. 

Hi Benjamin, I’m in japan and doing real estate investing here for about 8 years in different styles besides my full time job.

I'm a divorced dad to four and I'm working two jobs and never around to see my youngest.

I recognize there are other ways I could invest this cash (including another property) but I am being mindful of levering myself out too much in the current environment where job losses are more common in my industry (tech).

Consider population trends, job growth, and economic stability in these areas.2.