I have a BA in psychology(a.k.a a BA in BS Detection,) but my real educational background is in chemistry, physics, and math, which I’ve taught for 20 years at the high-school and college level.

I like Facebook marketplace and local FB yardsale groups.

@Riley Johnson pay for a people search or "Skip Trace"  You can even hire a private detective. 

Yes I know that there is more to it then that but in order to get word of mouth going, you have to actually get jobs coming in. facebook market place works

We’re a marketplace that connects buyers and sellers.

Here's what I would do:-Take the ad and post it on Facebook marketplace-People will inquire-Respond asking them questions to see if they qualify (for my renters it's credit score, monthly income and if they've ever been evicted or sued by a landlord)Have one showing at 5:30 PM during the week and one on Saturday around 11 AM.

I'm wondering the best way to list 2 rooms (FB marketplace, craigslist) and what documents should I provide up front to roommates (house rules, roommate agreement)Let me know your thoughts on this.

In my opinion, yes a realtor has more safeguards in place and usually has more protections for themselves and their business, but in a market like we have now in many places there are lots of brokers just signing agents in hopes of capturing more volume and from what I see, offering much less quality service than in a normal or slow market.I guess part of the way I view them, without a very established relationship- the wholesaler is the yard sale, craigslist listing or facebook marketplace item. 

I'm also considering Facebook Marketplace, Craigslist, Zillow, and I know there's a ton of FSBO websites, but I figured on there I would be receiving a lot of inquiries from realtors. 

Each offer a small number of free sends per month and together, we can do all of our leases for our 7-home portfolio- Stessa - Accounting - Free to landlords- Facebook, our own website and google my business as ways to have a professional face to the outside world and when our potential residents google us- Facebook marketplace, Zillow, Rentler - advertising for tenants - all free to usOur tenants are C/B class except for two mid-term/corporate rentals, for which we also advertise on Airbnb.Now, if it were not both my wife and me doing this, it would be a challenge.