You don't need to know everything to get started; you need a foundation to build on, and the rest will come through experience and then refining your education.You can build a basic understanding of investing in 3-6 months.

We got our own excavator which saves about 10k on lot clearing and foundation prep. 

It is hard because you feel like you are falling behind, but you are so right that I need to ensure that my foundation is stable.

If the tiny home is more like a medium home (600+ sqft) on a foundation, then you should be able to look at it as a "stick built" or normal home, just small.

Has anyone had experience with purchasing or considered purchasing a building with a sinking foundation?

From the floor joist being cut from the sill plates and the entire house needing brought to level, the foundation requiring correction, to the no slope rubber roof leaking and needing replaced when I say I renovated every square inch of this property I mean that literally.

A tent is not considered a permanent structure whereas a geodesic dome is a stick built home on a foundation.

Home inspection, sewer inspection, foundation inspector, lender, usually seller picks title.   

It explains the team that you should develop to have a strong foundation under you while investing remotely.https://www.biggerpockets.com/blog/core-four-real-estate-team

Pretty much all major components were newly installed / fitted and done to a tasteful standard (new metal roof, plumbing, electrical, kitchen, flooring, bathroom, doors, new hvac, decks, vinyl siding etc) and I have visited and walked through 3 times and even been under crawl space to inspect a repair that was previously noted on an inspection to the foundation after termite treatment which looked to be a good job.