@Michael MorenoYour proactive approach to building equity in your first property is a solid foundation for an exciting real estate investment career.

I think this would get me a good foundation to be able to then figure out what I would have to charge later on and give the experience to make the best choices when fixing up the duplex that I purchase.

When I mentioned to Charles Schwab, they said they don’t allow solo401k to purchase individual properties, only real estate investment funds. 

Other start-up costs such as appliances, which are normally considered capital improvements, become deductible in the current year under the de minimis safe harbor provision of the tax code.Note that some renovation costs will always be considered capital improvements regardless of whether or not a property has already been placed in service (for example, replacing the entire roof).Examples of renovation items you want to complete before you place the property in service:fixing structural issues (for example, cracks in the foundation)replacing an entire roof, floor, bathroom, kitchen, or plumbing systemadding a deck or new HVAC systemExamples of renovation items you want to do after you place the property in service include:painting installing appliances replacing a doorknob or windowrepairing an existing plumbing systemother minor repairs

Part of me wants to yell at those that refuse to understand that this is not only Possible, but it's a foundation on how I built my portfolio of properties.

But to summarize these requirements think big ticket items, roof, electrical, and foundation.

2 story homes are not very efficient to build, as the site work/foundation is very similar if you were to build a 3 story home.

It's advisable to create one and utilize it as the foundation for approving or denying applicants.

Income, and solid foundation for future investments Lessons learned?

There is not a persistent issue under the slab, but very infrequently there can be which has been a grading and neighbor directing water toward the foundation issue.