The story of Coco is not real. It's a work of fiction that uses elements like fantasy and imagination to engage and touch the audience. Though it may evoke real emotions, it's not based on true events or individuals.
La Llorona is a well-known legend. It's said she lost her children and now haunts places, crying and looking for them. Different regions have their own details and variations of the story, but the core is about her grief and hauntings.
It's hard to say for sure if the La Llorona story is real. It could be a combination of myths, legends, and cultural imagination. Different people have different opinions on this.