Needless to say, after closing I was working on the property when I heard a knock on the door.

As for off market, try driving for dollars, direct mail marketing, skip tracing phone numbers and cold calling, door knocking, anything you can think of to get in contact with owners and seeing if they'll consider selling.  

Of course this doesn't help your tax situation, but finding cash flow in rentals today is very, very challenging, and most deals I see people on this site going into are going to be cash flow negative.So what would I do: probably hunt down a modest flip, that I could turn my 200 into $240/250 in 4-6 months, and repeat.  

Next, with Covid-19 I feel door knocking may not be the way to go in order to move forward in the process.

Hello @Jake Freeman,Cold-calling, postcards/letters, and/or door knocking are good ways to start.

We were trying to rent for modest amount $1000 per month.

I have zero debt and have put together a modest seed to start out.  

But upon transferring the home, I would like to knock the house down and build a new home on the land.

I would personally try to negotiate with seller about the “assignment” on this too and just be upfront about you’re not getting a commission on the deal with the seller but they should be aware moving this deal with seller financing through a wholesaler- there would be an assignment fee (the kept down payment of 3-5% usually) Ideally that 3-5% should be yours then to retain if you do seller financing as with anyone else they would lose it (pay it out) too it seems likeSo maybe that should be leverage for you in an amount knocked off the purchase price - therefore helping over the terms somewhat.

The last time I knocked on the door she opened it and tried to close it in my face.