One atones, in part, for inadvertent sins, one is an extra offering the day before Passover began.
I have studied for years but have never quite understood all of the offerings and their specific purpose. What you said still is “foggy” to me. The Last Supper marked the beginning of Passover...which was a Tuesday night actually. Was there a sacrifice offered Tuesday? The lambs were slain on Wednesday at 3pm the same time Yahshua was crucified. His death made atonement for all sin...individually and corporately. Although there were two sacrifices on Yom Kippur. The first goat whose blood was placed on the Holy of Holies was for individual sins, the second goat, the scapegoat Azael was for the corporate sins of Israel. Are these symbolic of the two sacrifices you are talking about? Please help me to understand.