The potential legal structure of the entity that would be purchasing the multi family property would be an S-Corp or LLC with 3-5 investors.  

To help me in that goal, I am looking to add a side hustle to complement my corporate job that I currently work. 

Just a thought as you hunt for a good mentor - your chances go way up if you are able to offer them something as well (a complementing skill, helping at the office, etc) or to first find a deal and then offer to split it in return for guidance through areas you're unclear on.

Attorneys like to charge for setting up corporations like they are reinventing the wheel and pretend their admin isn't doing 90% if the work rehashing the same state specific templates.

When starting out doing investing in real estate just make sure you  forming some type of corporation or a LLC.  

Another thing you consider doing is to form some type of corporation or a LLC.  

We need to get a major employer or some corporate offices relocated to the Yo for those areas to ever rebound, and that would just be a start.  

The question is, whether to initiate a S-Corp or LLC for my passive income.  

The only exception would be if your rental property is in a C-corporation which it most likely is not as that is not a typical structure for real estate investors. 

Would a personal guaranty on a loan pierce the corporate protection of the llc?