Folk horror campaign start

Hey! Looking for ideas and inspiration for the start (and other moments ofc) for my folk horror campaign. I have a world, bbeg, main npcs so the world is set, but looking for ideas to start and invest the players in the world. I want the folk horror vibes and it must lead them to a ruined monastery. Anyone any good ideas for me to work with? Ghost, fairies all is good. Thanks in advance!