Private lending for the rehab cost

Of all the topics in real estate, lending, syndicating and crowdfunding are the most confusing for me. 

Simply stated, my LLC wants to be able to receive a loan from individuals to finance a rehab. I am finding so much conflicting information in regards to this scenario. I do not want to become a full-time syndicator or anything but I don't want to get in trouble with the law. These people are not accredited investors, just regular people who want a return on their money.

There has to be a simple way and term to permit this transaction with little paperwork and without an online platform as a custodian. Does a promissory note suffice for the private lenders?