Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

Doing anything at scale would likely take an act of congress, decades of litigation and environmental reviews, multiple huge overlapping federal bureaucracies working together, not to mention much of the available federal land is not useful for building housing on as it's in remote areas far from jobs with no water and sewer access, roads or infrastructure... so easier said than done. 

I created multiple LLCs using a registered agent company for $200 each.

@Max BellinoHolding company is really not needed unless you run multiple operational businesses like a property management firm, construction firm etc that you want to roll up into one entityHaving a holding company that holds one company you that owns real estate would have me question what’s the use case?

Off-market properties are not publicly listed for sale on the Multiple Listing Service (MLS).

For rents to increase faster than inflation, there must be significant and sustained population growth.Sufficient income to replace your current income: This will require multiple properties.

Quote from @Peaches Jones: You've asked this same question in multiple places.

START by leasing a property and testing your hosting biz. 

If you are focused on getting multiple assets at once, consider this:1. you really don't have enough available capital to do this safely right now and you will buy cash flow properties with cap ex which you will need reserves for2. you need $15-20k in reserves for each property you buy so factor that in3. when you try to buy multiple properties to start, you end up missing the mark on your first one because you are collecting and not curating your portfolio

Get quotes from multiple contractors to know exactly what it will take to get the project back on track.