I move quite a bit, although I have been here for just over 5 years, but this is the longest I have lived somewhere as an adult. We always make an effort to know our neighbors. I have lived in 5 houses as an adult, and I still have close relationships with neighbors from 4 of the 5 places I lived. Even the missing 1 out of the 5’ while we lived there we knew our neighbors and went out to dinner with a particular couple every so often.
I go and introduce myself after I move in, when I see them outside. Or, have a party and invite the neighbors to meet them.
My neighbors I am closest too have my house key, we spend time together, ask each other for help. I would hate not to at least have some minimal relationship with my neighbors who live immediately around me.
I also walk in my neighborhood, and have met people that way, who do not necessarily live adjacent to me.
Several communities I have lived in have an online site, or publish a newsletter with what is going on, or it might be posted in a clubhouse.