Hey Ram,
Great questions and let me do my best to provide insight as I do lots of business in NJ:
1. Where to find multi-family units in South and/or Central Jersey?
Scour every home site available and even sites that are not know for home sales, but sales in general - you may be surprised. If searching on your own is not sufficient, try making a connection with a new real estate team - there are bound to be real estate teams specializing in investor-focused purchases
2. What are some decent areas with low property tax and high occupancy rate?
This is the golden question that your own due diligence will have to answer - not sure any investor is going to give away exactly where they are investing as this would cause more competition haha.
3.Zillow doesn't bring me any units, my realtor also doesn't have knowledge on multi family units, what are my other resources you would recommend?
Zillow is not the only place you can see homes for sale, get creative and think outside the box. There are a plethora of websites where homes can be listed - not just the ones dedicated to home sales, too.
4. Would you recommend equity line of credit? or 401K loan?
Taking a loan against your 401k/equity in your home is a good idea, but needs to be utilized correctly. If you plan on purchasing your new property with a loan based on DTI, then it may be harder to qualify if you are leveraging yourself some more. That being said, if you are doing a non-income based loan, then you wouldn't have an issue qualifying still. But it's a tricky path and you need to make sure you are doing it in a smart way.
5. Any tips in multi family home investing?
Stay away from electric heating - this is a tip for all investing to be honest.
6. How do you calculate the Returns in a multi-family unit?
Same way you would calculate it in normal investing - once the property is 5+ units, it gets a little more nuanced. But for 2-4 unit investing, calculate it the same way you would for a typical residential property.
7. Are utilities paid by individual unit tenants?
I'm a fan of always making tenants pay utilities. You may need to lower the rent you are asking for by a bit, but it is way better to have a tenant using less water because they're the ones paying for it, than having them run the water for hours since they aren't the ones paying for it. This is also why I dislike Electric Heating. Electric heating compared to gas heating is much more expensive, so if the tenant is going to use it, definitely have them pay for it. But if they use it to excess, then the electric bill will be much higher than anticipated and if that month of high electric comes during a time that the tenant is facing hard times, they are more inclined to pay for their heating than their rent. Things to think about.
I hope all that made sense! Feel free to message me if you have any questions!