In my experience, being upfront about wholesaling and explaining that you’re looking to assign the contract has resulted in numerous signed agreements.

I'm not saying that it cannot be done, but man, you're signing up for a ride. 

We use Buildium to review applications, sign leases, etc.

What Drew said.Plus, insist on signed estoppel agreements before closing!

For example, a duplex that's on the market is selling for $440,000 and the tenants are currently paying $850 per month and are signed until next July 2025.

Just be 💯 certain that you'll be able to refi that HELOC debt off when the time comes.However...At this stage in your investment career, I would URGE you not to sign up for negative cashflow in the hope that "the market" will save you.

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.

Did you know that each week, several thousand people sign up for BiggerPockets, but nearly 10,000 RETURN to BiggerPockets after being away for more than 90 days (often for years). 

They will also have their rights extinguished and a judge will sign an order to have the liens released.This is a high-level strategy that requires a lot of knowledge and some cash as you will not be able to purchase these properties using financing.

The only work-around is to find a GC that you know well, (and who trusts you) and have them sign off on the experience.