There are a good amount of investors on here who could take down (including myself) a portfolio of rentals 

Frank, For a rookie investor with low capital looking to build a rental portfolio, the best strategy is house hacking: buy a small multi-family home with a low down payment (FHA or conventional loan), live in one unit, and rent the others to cover your mortgage.

Also, does this apply to an owner who owns and manages their own portfolio?  

You can hear real-world examples of how others have built their investment portfolio and (hopefully) learn to avoid their mistakes.4.

I just want it to work and be a positive experience because I know that will keep me motivating to continue investing and building my portfolio.

I rent my portfolio out as LTR and self-manage.Good Investing...

These were people who seemed more interested in adding an investment to their portfolio than really operating a business.

With $150K, I could easily put together a portfolio of 6 rent properties from deals I see every week, including last week.Just get started.

This experience can help you scale your portfolio over the next few years- Local properties appreciate faster, which allows investors to reinvest their equity into more local multifamily units OR other markets where the cost per unit is lower (i.e., Philly, Upstate NY, etc.)The Bronx is arguably the best borough to consider the househack strategy.

I have a property that doesn't align with the rest of our portfolio's strategy and we are ready to sell it.