Passive Investment - Buying and holding performing notes for interest income and or investing in debt fund/partials ownership Active Investment - Buying non performing notes to either modify to reperformimg or foreclose for real estate ownership; “working” the notes in your portfolio; or “creating” high yielding investments through various meansNote BUSINESS - Running a note fund; syndicating notes, buying and selling notes, creating partials, brokering notes, etc. 

I am retired and working on career #2 and 2 of 3 of our kids have left for college - our oldest is headed to UConn for her PhD (6 years) and instead of paying to rent, our thoughts are to do a version of a house hack with buying a house/condo and renting out one to two rooms to offset the costs of her rent.

what’s the best way to use OPM to buy my first house to rent out?

What are some companies that buy these loans?

LOL) that week just flew by, too busy trying to buy gifts for this Christmas party at my friends house, and too many last min change of plans...

So don't buy rental but keep buying primary locally... you can even double your networth very quickly buy buying broken-home and flip it around. 

My brother and I have sent out direct mailers, very generic we buys houses cash with a phone number and a we buy house sign for the picture.

What are the disadvantages of buying a 2-story duplex? 

(In other words, if it's too high, then I can cancel the buy and not have to lose any money)2.

They will be a great resource to guide you in the right direction.