Buy-and-hold newbie question - Section 8

[Adam Brown]

Greetings:

I wanted to know any considerations I should have prior to buying a multi-family. 

I am interested in purchasing a multi-family house, for a few hundred thousand. The problem is I am afraid I am paying too much, and I am worried I may get stuck with a huge debt that will not off-set , if I sold at fair-market value down the road. How should I proceed? 

FYI 

My cousin has done this and will be holding my hand the entire time, however, he has held his properties for decades, while I would want to sell in 5 years. 

Thanks!