@Alexandria Sorrell  Most of the online information (Jerry Norton, Max Maxwell, Clever Investor, Wholesale Inc.) is an ultimate effort to sell you on their software or program; be wary of this and they still have valuable content and information.  

Start by reading the Ultimate Real Estate Investing Guide: https://www.biggerpockets.com/guides/ultimate-real-estate-investing-guide/introduction 2.

My ultimate dream is to add a 3rd unit (ADU), garage to fit an Earth Roamer campervan (29ft x 8ft), a den/family room for the main unit, and a rooftop deck that can get up high enough to see the skyline/mountains (28ft) but zoning looks to be holding me back. 

When you ultimately take out money out of the 401k when you are retired you will pay taxes again on those withdrawals.

Ultimately you'll probably want to have a structural engineer take a look at it.  

I find myself leaning towards properties that I can rehab on some level to ultimately gain more equity overall.

Also, I was approved for a 1st time home buyers grant (another program through Wells Fargo that I ultimately didn't use because of deadlines/other restrictions) which was approved for anything "residential" (up to 4 units).

Ultimately, it turned out that the wife had mistakenly written down her husband’s SSN down wrong on his application and it was off by one single digit.

But ultimately, leveraging will usually give you much higher returns.

If you're ultimately going to be managing the single family home, I highly recommend finding and vetting the tenant on your own.