30k starting out. Critique my plan?

[William Houstian]

I have a full time job but I want to build a rental portfolio and become a cash flowing Real Estate Investor as quickly as reasonably possible. Currently I am renting an apartment until September of 2018. My plan now is to owner-occupy a house that I will buy at that time to get the benefit of not having to put down 20%. Then in a year I will repeat this, move to the new place, and rent out the old. This allows me to buy more properties as I will not need 20% down each time and will be buying them owner-occupied. The downside of this though is that I will only be able to acquire properties at the rate of one per year. I want to build my rental portfolio faster than that. The other options I see are to buy cheaper houses on which I can afford a 20% down payment, or to flip houses and use those profits as down payments on rentals. Once I own the first property I will be able to take out HELOC to potentially do this but I just want to know if this all makes sense and what options exist I may not be considering. Thanks. A lot of my plan centers around the fact that you need 20% down if you are not owner occupying. Are there ways around this?