A modest couple-hundred dollar cash flow is possible with low maintenance, self-managing, etc. etc. for the owner occupant among us, but if all four units are rented out, a cash flow exceeding $1,000/month is more than possible.

Qualification involves being both self-employed and having no full time employees in any business you control.The Checkbook IRA LLC is also a great vehicle for diversifying retirement savings.The best thing to do is speak with a few professionals who offer checkbook control plans of both types and determine what the best fit for your situation both today and for the long term may be.

He is 72 years old and says he needs that time to move him self out.

I know you will be able to get a really good handle on how the process works and what you need to do in a lot shorter time than it took you to earn the money you are getting ready to invest, so spend the time to educate your self don't just trust that what is being told to you is accurate. 

Through commission to your Corp, you might be able to decrease your self employment taxes.That statement has many assumptions built into it.

My self storage business seems to meet most of the requirements for being excluded from my total assets - the business/real property is owned by a family-controlled pass-through LLC, has employees but fewer than 100, provides services in connection with its real estate holdings, and keeps separate bank accounts in the business name. 

I'm currently trying to get out of an apartment that I'm paying $1300 a month for right now, and I know I can find a 4 plex or more in which I could be actually making a little cash flow/house hack, I'm currently self employed and have been for three years (I believe might be an issue with the lenders), and have about 10K saved for a down payment, and I have a friend who wants to invest with me who has a large sum of money but bad credit so I don't know where to begin please someone at least tell me where to start?

Congrats on doing so well starting out self-employed. 

In your expense estimate be sure to include property management (even if you self manage), maintenance/repairs, vacancy, utilities, lawn/snow care, insurance, taxes.

I may have heard of people self-closing quickly with minimal risk after an owner and encumbrance search and DD with the city and county as to permits, utility bills, code violations, assessments and taxes.I may also have heard this isn't recommended for beginners at all.