I'm looking to get started investing in the DFW area.

Goal would be to acquire 20 rentals by the age of retirement, with some already starting to be paid off.I am in the same boat as you, and I focus on safe appreciation all day (small cash flow for safety and then focused on markets on that appreciate). 

Start with the address and details about the rental.Create a section for tracking the lease information.

It's not easy to admit mistakes.I think you should start by eliminating the get-rich-quick mindset.

Live under your means and start thinking about investing in Real Estate.In your position the thought of finding a duplex to house hack, live in one side and rent the other. 

This kind of govt nosiness and overreach is why I initially decided against the financial planning industry before starting in credit. you can thank 2008 and all the fraud that went on for that.

From my experience working with over 400 investors, those who start with house hacking scale much faster.Good luck!

It depends on your financial strength, the quality of the property, how many properties you own, etc.I like to start with one significant expense and three months of vacancy.

Quote from @Paul LaValley: I live in Tucson and know Tucson really really well so I want to start here and then jump up to include Phoenix area. 

BiggerPockets is full of resources designed to help you along your journey, whether you are just getting started or a seasoned investor.