Answer:
When we speak of rising action we refer to the moment in the story where suspense or tension is created through a series of events. All these events are those that will later give rise to the climax, where all the problems of history will be solved.
The rising action in coco begins when Miguel, being a fan of Ernesto de La Cruz, enters his grave and steals his guitar. When they discover him, he runs away and that's when he enters the world of the dead and the story begins to unfold.