Leviticus contains two pieces of narrative and no more. In chapter 10 two sons of Aaron offer unauthorised fire and are killed by it, and their father is told not to mourn. In chapter 24 a man of mixed parentage blasphemes and is stoned. Everything else, twenty-five chapters of it, is instruction, and the book is spoken almost entirely by one voice addressing Moses at the tent of meeting.
The structure is orderly. Chapters 1 to 7 set out the kinds of offering and who eats what. Chapters 8 to 10 consecrate Aaron and his sons. Chapters 11 to 15 define what makes a person or a thing unclean: certain creatures, childbirth, skin disease, mould in a house, discharges from the body. Chapter 16 gives the rite of the Day of Atonement, including the goat sent into the wilderness that gave English the word scapegoat. Chapters 17 to 26 form a distinct block, and chapter 27 handles vows and valuations.
The purity laws are the part most often misread. They are not sanitation, and no ancient reader treated them as such: childbirth is not unhygienic, and the forbidden animals are not more dangerous to eat than the permitted ones. What the system does is sort the world into categories and treat what falls between them as anomalous. Creatures are classified by where they live and how they move, and the ones that do not fit a class cleanly are the ones excluded. Uncleanness is mostly not sin, it is a state, it is usually temporary, and the remedy is a procedure rather than a punishment.