We like doing the hard work of doing due diligence, researching property histories, getting estimates, negotiating contracts, etc.We're also going to be looking to buy and hold in the near future possibly by BRRRRing.

I would like to invest in the West Palm Beach/Jupiter area.

There is lots of information on how to analyze publicly traded REITs as well.

You can't rent out a PO box and live there.And yea that sounds like a huge red flag to me. 

A friend and I created one recently:https://drive.google.com/file/...It was meant to compare costs between different lenders, but you can use it to just see costs from one lender as well.

I would like to know how the process of building loans works and how much funds I need to have.

Like everyone else stated with appraisals, it will be curtailed to your scenario.

I also don’t like renting really nicely rehabbed properties, most renters don’t take care of properties as well as we would hope.

In addition to the interest of the loan, you'd also be paying this as well. 

@Jose Saladin you will likely not get a CO (certificate of occupancy) to be able to legally rent this out.