Charlie, no money financing is a challenge, although not impossible.
Our first rehab was mostly paint and a little sheetrock repairs.
I found a painter friend that gave me all his 1/2 cans of paint and culls he had in his shop. we mixed it all in a big trash can , (FYI it comes out gray) he was happy to get rid of all the old stuff he had, we were happy to get the free paint. you can go to job sites of new builds and get some cull lumber , you can pick up some deals at the Habitat for humanity type stores. They may not be new but they are functional.
Once it is rehabbed possible refinance with the equity's is an option for better interest rates.
The first one is the Hardest.
Remember don't fall in love with it. clean and functional, will rent.
Funding sources I have used are ,
Credit Cards,
Lines of credit on my home,
borrowed from hard money (Family).
Income tax refunds.
taken my refund and bought certificate of deposits, and borrowed against them. (they can only charge me 2% more than they are paying me) . Also building credit with the bank!
After you get a few under your belt, the portfolio lenders will begin talking to you.
They have always liked that I have the W2 Job that pays my bills, and that I always say I am going to reinvest all gains into my properties,
Each on of us find our way of investing, You have already done something I have never done. Bought an owner finance!! Congratulation's your on your way!!
Now it's time for sweat Equity!!
Don't be afraid to ask for help. if something comes up your not familiar with. you would be surprised who knows what.