Perhaps it is purely an American phenomenon that schools are regarded as communities. When I was at school here in the UK there were hardly any co-educational schools, so no dances, proms, trips, etc, we just went there to learn.  Dating whilst one was of school age was frowned upon.
Similarly the Parish never seemed like a community either. There were a few social events per year which only a fraction of the parishioners attended. There was the CYMS (Catholic,Young Men's Society) which despite its name included men of all ages who used to meet in the Church Hall to play snooker and drink at the bar. The ladies had the Children of Mary but I don't know what they did except that they didn't play snooker or drink at the bar.