with the BRRRR/Flip idea utilizing equity from the home, you are best off to pursue the garage idea but there are a few considerations to take into effect.

However, I have no clue how to pursue this goal or find potential sellers willing to utilize this method.

For the contract stuff you should talk to a lawyer about that and someone already utilizing the strategies you are discussing, know the risks of the strategy you want to implement before moving forward and maybe try to shadow someone already doing them.Again my initial recommendation is that you put your work ethic and drive toward something with a more predictable payout, stop wasting hours working for Walmart, bring your earnings up and continue learning about this industry and then make a move for something bigger once you have a nest egg built up and have taken the time to develop enough skills to make it in whatever you decide to pursue.

I’ve calculated all cash invested including closing costs, Mortgage, utilities, insurance, furnishing the unit, supplies etc.  

Own the land, utilities checked out, the permitting is almost done, have a contractor lined up, and about to break ground in 1-2 months. 

Can we turn off the utilities?

What are local business license requirements, what does the water utility company require, and gas...

They have 4 kids, have never paid a day in 24months, pay their utilities on time, house is always spotless and the outside is always picked up.

Realtor friend who I've known for a while found it for me after the original buyer backed out, we were able to get it utilizing a hard money loan and private money to finance the rehab leaving us with only about $25K invested in it.

Thankfully I was protected by the moratorium so he couldn’t evict me for non-payment, so I was able to live rent free and didn’t have to pay utilities.