Tribes & Indigenous Cultures - 4 free documentaries about rituals & ancient ways.
Start with How to Survive Brutal Pain Ritual (Bullet Ant Challenge) (35 min, National Geographic), then Sacrificing Hundreds of Buffalo for One Funeral in Indonesia (25 min, VICE). All 4 documentaries here are free to watch from their makers' official uploads. To read deeper, the top-rated book on rituals & ancient ways is The Hero with a Thousand Faces by Joseph Campbell.