Some channels like Youtube and Google have better segmentation options for real estate.Don't get discouraged.

I recommend you do a google search for "real estate seller financing" and educate yourself through some blogs, then have a conversation to see if the two of you can agree on terms that work for everyone.Be sure to use an attorney to draft the documents, not the same one the seller uses.

welcome @Cam Caraher and congrats on joining BP, this place is the start for many, sure was for me longer ago than I care to admit.I'm not personally in your market, although was born in dorchester and grew up in NH, but this is a great place to meet locals.If you have not already a great starting point is the Meetups posted here, just search for your area and see if any meetups are happening. 

Apparently the seller's title search didn't reveal a lien (ours did) which wiped out more than 80% of their remaining equity. - Expect rehab costs to exceed initial estimates (maybe double)!

I search them on LinkedIn, Facebook, and all social media.

You can also find real estate investing groups through meetup.com, Facebook, or a Google search.

Still searching for the perfect sewer line, most have at least some imperfections even new construction.

You can also check meetup.com or search Facebook for real estate investment groups, clubs, or meetings in your area. 

I'd simultaneously search for duplexes especially those with value-add potential.Regarding volume, the Suffolk towns with the most listed 2-4 family properties since '23 have been Lindenhurst (46), Huntington (22), Patchogue (21), West Babylon (16), and Bay Shore (15).Riverhead has had 10 listed small multifamily properties in this timeframe so it isn't too far behind. 

I’d search out an established local operator and pay them to operate it.