Not able to house-hack as I have a home that I will be securing a HELOC from and looking to invest locally (including Union City, NJ area). 

I was wondering if anyone had any valuable input on what to ask a small credit union if I’m looking to take out a loan to buy a property....I don’t have an LLC, I do want to own property as a business, I have good credit ~780, I live in Columbus Ohio, I have two full time jobs; turnkey is ideal....

I checked with both my normal business and personal credit unions and they could not come close to that. 

Regional banks and credit unions are generally the best places to look, and HELOCs vary greatly by lender... it's not like the Fannie/Freddy stuff where you jump through all these hoops to shave 0.125%, it'll be easily 0.75% or more of a spread between lenders. 

HiI am planning on building a ADU in Union City, CA .

Alternatively, you could put the money in a CD with any bank or credit union. 

I assume you would also recommend meeting with local banks and credit unions?

I'm trying to determine what a bank or credit union will give me.

I currently bank with a credit union, is that a good option to apply for a mortgage loan or should I branch out?

Local regional banks and credit unions are the best place to look for HELOCs, not mortgage companies or brokers.