I don't remember their names but people from the War College helped us redo the electrical and plumbing for cost which was amazing.

I was able to convince my lender to allow me to do an air pressure test of plumbing lines, it passed and so I provided that info to the lender and they accepted it in lieu of turning on water.

I assume it has sewer/septic, water and electric and they 2 tiny homes are plumbed/wired?

roof on, framing done, pool started, rough plumbing done, electrical rough will start next Thursday, A/C install next Tuesday. 

For example, if I want to install new plumbing in the bathroom because the old one is old and broken, would I need a permit to do these fixes? 

Electrical and plumbing all updated within the last 4 years.

It's a former adult care home, so the layout is shared bathrooms, and this would allow me to not have to change the plumbing layout while offering a competitive price-point and unique experience to travelers.

I plan on taking some introductory classes for plumbing + electrical + carpentry + ???

We backed out of that deal because there was a freeze that hit Texas market, and that freeze caused a bunch of plumbing issues.

With fresh paint throughout inside and out, brand-new roof, dual HVAC systems, updated water heater, stainless steel appliances, lighting fixtures, outlets, countertops, and PEX plumbing just to name a few.