Join all neighborhood groups on Facebook that you want to farm. Watch this video if you don't know how: https://youtu.be/ChT0xuB54K0
Go into each group and comment on 5 different post in the group. Any post, just be contextual to the post. Bring value where possible. Simply put, engage.
Pick 3 post and go comment on an existing comment on that post. AKA, have a digital conversation.
Pick 3 people from the group, and message each one on one and start a conversation via messenger. Bring value, focus on commonality and connecting, not real estate.