I'm currently looking for someone to manage a 2 unit property that I own and househack in Bayridge Brooklyn. 

(Or a lot if you're dealing with a scam turnkey company, of which, unfortunately, there are a decent number.)BRRRR is much more active, you buy a fixer as you note, oversee the rehab yourself and then either manage yourself or find a manager for. 

How is your Property manager - ok or terrific?

To build and diversify, I’d recommend starting small—maybe a duplex or triplex—to get a feel for managing property.

If you're going to self-manage you should definitely pick market(s) that you are familiar with.

Add maintenance/cap ex, vacancy, PM, misc and this is likely negative more than $500/month even if self managed (much more than the negative $200 that you indicate you are ok with) 2) if you are behind on mortgage, how are you going to handle being negative $200/month, or more like negative $500/month?

You could form a single LLC for all properties, which is easier to manage but carries shared risk, or you can create an LLC for each property, which offers better protection at the cost of more administrative work.

Do you need a property manager?

Someone has to manage the rental, and it's very active.

The other fellow agents in our office are ALWAYS down to help each other and intro to other investors, contractors, property managers etc.