I have a tenant that I am self-managing. 

If you need a good attorney, I can connect you with the one I use for our management side. 

I've already invested in a duplex in NJ (I'm renting it to two families and managing it) and a single family in MI (living in it).

Please do not hesitate to contact me at [Your Phone Number] or [Your Email Address] should you have any questions or require further clarification.Sincerely,[Your Name][Your Title, if applicable][Your Company, if applicable]Hope this helps.

Take a look at some trade accounts and a line at the Big Blue and Big Orange if you are going to self manage.  

You're looking for increased cash flow, so managing more doors and/or strategically utilizing leverage can make a certain sense there...but as you mention financing costs aren't as rosy as they were 2-3 years ago. 

Is your DSCR ratio greater than 1-meaning are you cash flowing (according to the lender's criteria of mortgage, property taxes and insurance (and HOA) if applicable).

I'm structured and want to pursue something in real estate or money management.

They may feel a sense of entitlement, and they may not even be good renters.Unless this is some unique situation like a ranch that requires special skills to maintain the property, I recommend you remove the caretaker, spruce the place up, and put it on the market at market rates.I also recommend you look for a professional property manager that can help you navigate this immediately.

how will they manage the property?