First Investment Insight/ Advice

[Nathan Astrup]

Hey Team,
Im a real estate agent in Cleveland and I'm gearing up to make my first investment.
Background: Strong backround in construction and real estate.
Finance: minimal down payment, financing available.

My niche is going to be buy-and-hold rental supplemented by an occasional rehab.
Im looking at duplex properties in the 50-70k range and I'd like to live/rent my first and save money for subsequent investments.
I've calculated for 10% vacancy yearly, 15% repair funds, and 25% emergency replacement funds, PITI and possible PMI. These are derived from Gross Operating income. I'm basing rents off comparables and they are on the lower side. I ran two sets of numbers (me occupying, and me not occupying a unit) And I plan to contribute monthly to add to the GOK, god only knows fund.
Are these safe and conservative numbers?
What are some potential pitfalls/oversights?

What are some viable options for lending that positions me with as little of my own money down while minimizes PMI if not eliminating it?

I guess this could be another topic on it's own, but my long term goal is to have 20+ properties paid off in 25-30 years. I've yet to find literature about how people have done this but I know it's possible. What are some ways investors aquire that number of properties, short of having tons of cash!?

As always, thanks for your input and support.