This is the law of the sin offering… (Leviticus 6:18)
We have previously established that a mitzvah can have many steps but these are part of the whole, not individual mitzvos. (See Mitzvah #115, regarding the burnt offering.) By way of example, if I wanted a deli man to make me a turkey sandwich, then “put it on rye bread,” “lettuce and tomato,” and “no mayo” would all part of one “commandment” of making a sandwich, not individual “commandments.” Not until I get my sandwich on rye with lettuce and tomato, hold the mayo, could we say the “commandment” was fulfilled. If I got a sandwich on white with no lettuce and tomato, the deli man could not claim to have successfully performed the obligation to hold the mayo; he actually did nothing. (This example is just meant for illustrative purposes. Do not “command” the deli man to make you a sandwich; ask nicely.)
A korban chatas (sin offering) could be brought from cattle, sheep or goats of either gender and most any age; pigeons or doves could also be used. Some sin offerings were private and others were communal. Some were burned in their entirety and others were eaten. (See the next mitzvah for more on this detail.)
The Sefer HaChinuch says that we cannot hope to understand the meanings underlying every individual aspect of each type of sacrifice, which differ in the times and places they can be eaten, the locations in which the blood was sprinkled, and in other ways. The main obligation is to bring the sacrifices and we shouldn’t get too bogged down in the details of each.
The obligation to follow the procedure of the korban chatas applied to male Kohanim in Temple times. It is discussed in the Talmud in tractate Zevachim, on page 52b-53b. It is codified in the Mishneh Torah in the first chapter of Hilchos Maaseh HaKarbanos. It is #64 of the 248 positive mitzvos in the Rambam’s Sefer HaMitzvos. The Ramban (Nachmanides) does not count this among the 613 mitzvos, nor does he count the processes of burnt offerings, guilt offerings and free-will offerings. His logic is that the commandment to bring such sacrifices is sufficient; we do not need an additional mitzvah to tell us to follow their prescribed processes.