There are lots of expenses you should try to budget in like vacancy, repairs, capex, utilities (in NJ the landlord pays common electric), legal, etc. so you could be in the red for quite some time. 

@Dan Handford has a great article about the red flags to consider before investing passively in any opportunity

The market is red hot right now so your best option would be a straight sale if the property is that desirable.

So you would have to go through the trouble/expense of finding a new renter, charge the old renter for the days occupied, and you'll lose the discounted rent you gave in the first place.If renters want to pay up front, it's a red flag.

any red flagsEveryone input will be very appreciatedThank you all and happy holidays

As others have mentioned, price point will be your biggest issue as the 2-4 unit market has been red hot all year long.

I love the Austin market, but it's red hot right now. 

The state was "red" by like 1.5% this year.

I recommend more often when you have a problematic tenant that gets behind on rent, violates the lease, has complaints from neighbors, or other red flags.

Huge red flag.