Target Multi-family..whats next!?

[Terrell Sapp]

My girlfriend lives in a MFR (4 unit including landlord in basement) and her landlord doesn't do much for the place as far as cosmetics, even a broken handrail which is hazardous. I don't have much information on him but Im sure I can find out more.
I suggested to my her that I could talk to him regarding selling the property, i would love to owner occupy it but have little knowledge on how to do so. Instead of using direct mail I'll speak to him in person, maybe door knock. This is a plan of mine to rent out a MFR. I have knowledge on wholesaling and little in regards to renting out, heres what i would like to know..

- how to go about it?

-what to say?

-is it possible to have a property manager for it? 

-how to check to numbers?

-what exactly should I be checking for?

Newbie looking for as much advice/tips as possible from the experts ! Thank you