You can find a lot of meetings on the MAREI calendar, both MAREI's meetings, local landlord group meetings and a few other meetings hosted by our members. 

He owes them some money for work that they did and they filed a mechanic's lien on his property 3 weeks after he received the bill which was also one business day before he was scheduled to sell/close on the property.

It will be remote, but since you live there now, you probably already have connections who either already know the house or local friends to find you good people to service things as needed.  

I inherited a partnership in a 22 unit commercial building with 8 restaurants, a grocery store, a couple of personal care services, and various other businesses.

Beg family and friends to fund it for you.They "might" do it if they see you've learned a lot and your business plan sounds very solid.How do I know this "might" work?

If they’re underfunded, you could get hit with special assessments.Since you want to stay local and focus on cash flow, commercial makes sense, but have you considered industrial or flex space?

You're a business owner now nothing wrong with that.   

As far as LLC structures and tax strategies you should find a CPA who has experience with real estate and small business.  

There's no fixed max size beyond local zoning rules.

Michelle Wang,With all due respect, you should make plans to be in another business once you're out of Real Estate Investing (Residential, Income Property).There are Members of our MassRealEstate dot net Association that come crying to me about similar situations as yours i.e.