Need legal advice for agreements

[Kameron Fontenot]

Hello Investors,

I am seeking out to figure out if I am going to be safe or not. I have a seller who is also an investor. They spoke to me about finding a buyer to agree to over a certain amount and anything after that I can keep. I have found a buyer and before I make it certain with my buyer on a specific price, should I get the home owner to sign an agreement? The homeowner didn't want to put it in contract with me so the house isn't tied down and so I am not on a time limit. He did agree to sign anything if I wanted him to. 

If I want to have an agreement do I need an attorney to write it up?

He also tried to reassure me that I would get my money because his reputation is on the line. I feel he is being honest, but being a novice I do not want to get taken advantage of.

TIA,

Kameron