Rental? Newbie

[N/A N/A]

Hi. First off my name is Joel and love this site. I'm only 20 so I am very new to this investing thing. Anyways, I found a 4-unit, for $110,000. The rents bring in 2000/month. It has positive cash flow of 4-500/month so I am very interested. My question is it is fully rented but the one renter is new and all of the rest were there less than a full year. Should I be scared. What kinds of questions can I ask the renters to be sure they won't rip me off without coming across too judgemental. Thanks. Any other tips would be appreciated. Going to go through it today with the realtor.