Looking for suggestion on how I can do to a maximize return

[Calvin Liang]

Hi, Oakland investors. I am a newbie in the rental market. I started to look for a good investment a few months ago. I don't have a lot of cash, so my downpayment is most likely 5-10% for a property within 800k range. My family friend is willing to sell one of his property to me. 

It is a 5 units building with a commercial unit on the first floor, near San Antonio Park. It's also tenant occupied, the rent he collects is somewhere between 5-6k per month. He's asking for about 700-800k(we haven't talked abt all the details yet) 

What do you guys think it's a good price for this building and should I even try with so little downpayment? What should I look for to come up with a good plan to maximize my return?

I really want to come up with a win-win deal with him.

I do realize things like rent control law in Oakland, and with little cash like I do it's hard to do anything. I really want to get my feet wet on the rental market and learn more(My family friend also has another property right next to this one. 

I would greatly appreciate any advice from experienced investor like you and appreciate your time reading this.