My wife and I started out buying a two-unit apartment house about 7 years ago with a similar goal... buying 1-2 small multifamilies per year to hold and pay off the mortgages to cash flow supplemental income.

Also to retire he needs the income from the rental to supplement his pension.

I will get as many as six, and use the best 5. 2 supplement the best 3.

I’m planning on purchasing a few OOS properties to supplement Ca properties.

You can use cash generated from the losses if any to supplement your 1031 purchase.  

My older brother, who is currently flipping his first home in Philadelphia, enlightened me on the possibility of real estate as not only a supplemental income but more so a way out of my house via house hacking.  

Then, supplement with your own research.BPO's are beyond worthless.

My husband and I have a goal to purchase some buy and hold units to supplement retirement in 10 years.  

Unless Chicago experiences similar appreciation as LA, which I don't see based on pre-recession vs. post-recession median home sales price numbers, the implementation of a Rent Stabilization Ordinance will discourage investment from buy-and-hold investors, who will start to see a squeeze on cashflow (restricted rents w/rising property taxes) supplemented by sub-par appreciation gains.

I'm definitely going to stay on bigger pockets because this is a very powerful and free tool to have, but I'm also looking to supplement this really awesome tool with other tools that are out there.