Experience owning + managing a multi family unit

[Swetha Mandava]

hi all, I'm a newbie investor based out of state. I recently lived in philly for a couple of months and loved my time there and hence decided to invest in the real estate there. This is my first real estate purchase so i'd love to get your opinions on it

I'm conflicted between purchasing multi family units (cash flow neutral) and single family homes (cash flow negative but better appreciation)

For multi units in point breeze
1. What is a reasonable cap rate? I can't get past ~4.5%
2. Any recommendations on property managers? 
3. What's a reasonable vacancy rate in this area?
4. Right now for computing cash flow, I'm estimating a vacancy rate of 6%, property management 10%, Operating expense 10%, Landlord insurance 2k/year, utilities 230/month. With these, my cash flow / cash invested is <1%. Is this normal for the area?

What are some tips that helped you the most when investing in Philly? 
Thanks in advance for helping out.