@Mallikarjun Reddy Pateel most important item to verify is that rents are indeed being paid and how much and when etc.

I have one trusted guy that does the interiors, and then I end up finding other contractors for big items (plumber, roof, electrician, carpet etc). 

I used traditional financing, owner occupied loan, and I house hack the property which allows me to live there for free.

Traditional Investor Mortgage, with 15% down.

Our goal was to gain assurance that there were not large, unseen items that would potentially threaten the opportunity we saw in purchasing the property.

Going the MLS route and using traditional financing is going to be much easier and less risky for someone starting out.

Some of the hidden costs can be specific to the area that you're building in, but your GC will be able to tell you what scope they cover, what scopes they don't cover, and give you guidance on who to contact for recommendations on items they don't cover.

Will hop on a call with attorney regarding this item.

HELOCs are all over the place, as they aren't regulated the same as traditional mortgages. 

What should I do with the money I am earning right now in internships if I plan to begin investing in real estate as soon as possible after graduation (whether that's house hacking or traditional rental)?