They also operate at a macro level that it matters.

The $100 loan (from each investor) would be a business loan directly to you, under the following terms:1 - 10% simple interest.

I’m doing simple basic base hits of 8-12 percent consistent return.

How much of an operational improvement (i.e. increased revenue, decreased costs) can you reasonably expect?  

@Daniel Dietz , If this deal is done via LLC, you need either article of incorporation that is detailed enough and plus an operating agreement. 

We use to own and manage 4 short term rentals in Phoenix and know the amount of effort it takes to operate it successfully. 

Smoke detectors , working toilet working sink , good working outlets , functional doorknobs no trip hazards .. simple stuff !

I have experience with agriculture land and commercial Real Estate and was wondering how many units is a good size for a first timer in multi units to purchase, to get to know how they operate.

If I had to go back to 1996 when I started, I would do the same thing - get a small multifamily and live in one of the units.One thing I'd change is that I'd operate on of the units as a short-term rental/corporate rental.The technology wasn't around then, but it sure is available now. 

My wife and I currently own and operate a small cabin rental business in Southern Colorado on the Rio Grande River.