I have access to Private money in MI, dont understand the payback

[Mike Lewandowski]

I live in Southeast Michigan and I am interested in the BRR method. Buy 3-4 rentals and refi strategy. I have 70K of my own money and I have access to 100K of private money. I will be attending my 1st REI meeting in 2 weeks in the local area. I have been listening to Podcast nearly 24/7 and reading non-stop. I have also been looking at properties in the downriver area the past 2 weeks to Brr. My question is how do I pay back the Private money? It's still unclear to me. Is this done on a monthly period and then when I refinance I pay back the borrowed money? This is what I don't fully understand. Also if a deal presents itself at a REI how are agreements documented? I've never met any of the memebrs yet are these deals done on good faith? I would think not