They were not managing the deal. 

You will have to first notify the tenants' case manager at their local housing authority who will likely want to dig into why you don't want to renew - in which case like others have mentioned, it's a good time to lawyer up and/or document every instance of them breaking lease guidelines. 

(2) Are there any property management companies that can help us buy, finance and manage the apartment complexes and where can I find them? 

Then, have the document reviewed by an attorney.For example, suppose two people decide to pool resources and invest together.

I manage my own STR's in PA and don't really want to have property managers for STR's because it's a market that requires more attention to details.

This book got me off the sidelines and in the game: Build a Rental Property Empire by Mark Ferguson and this book elevated my landlording methods: Managing Rental Properties by Heather & Brandon Turner~ Lindsey

(Imagine if they decided to reclassify their rooms as STR to lower their costs.)

Better to find a roommate that you know for the other room if you decide to do this.

Speak to them about their experiences and satisfaction with the firm.Look for testimonials or case studies that demonstrate successful investments and positive investor experiences.Evaluate Transparency and Communication:Assess how transparent the firm is about their operations, fees, and processes.Ensure they provide clear and regular communication about your investments, including updates on loan performance and any issues that arise.Analyze Risk Management Practices:Understand how the firm manages risk.

Since then we have moved out of the area and been renting it out for the past few years.We are slightly negative on cashflow, about $100 a month or so when you account for a 3rd party property management service and expected repairs etc.Our challenge here is the home is old.