Looking for advice. Buying a multi-family as my primary residence

[JP Morales]

First off I have to say I love this community and all that I have learned from it. Was hoping I could get some nuggets of wisdom from everyone here.

So currently I own my first home that is a 1 bedroom co-op in Westchester New York. I’m at about 50% equity in my apartment, which would provide me a sizable down payment if I sold. Ideally that would be my beat option because my liquidity is not the best, after starting a family. 

I’m looking to purchase a multi family, ideally a two family. Would love to rent one side and live in the other. The going rate of rate for a private home with for a two/three bedroom apartment for rent is about $2500 conservatively. 

Based on market values in my area I’m looking at a price tag of $450k to $600k. I’m a little apprehensive of pulling the trigger. Without first selling my first property and jumping into the next, it leaves me with a big overhead. 

I used the rental property calculator on the site and it gave my a cash on cash ROI of -20%. I've been reading double digits in the positive is where you want to be at.

Finally I considered using a section 8 tenant as a guaranteed source of income for the second unit if I were to purchase a two family. 

Any opinions or guidance would be greatly appreciated.