I don’t agree with the sacrifice aspect of it at all.
First, it says God made them garments of skins and clothed them. No animal death is mentioned at all. He could have created those skins without killing any animal.
Also, God doesn’t meet His justice by performing a sacrifice on behalf of someone else. That would be like a Judge going to prison for a convicted felon. God accepts sacrifices from those who sin against Him.
Cain’s and Abel’s sacrifices were not atonement sacrifices, they were offerings of “firstfruits,” a thanksgiving offering to God in thanks for the bounty of flocks or harvest. There is no record of either one sinning at the time the offerings were made.
Finally, if this were a “first sacrifice,” why on Earth is there no record in all of Adam’s 900+ year life of him making further sacrifices? You’d think he’d be offering up animal after animal to try and make up for his sin and hopefully attain mercy and get back in that garden.
I would interpret the skins as merely symbolic of need for something (protection) once they are put out of the presence of God (out of the garden). Being outside of His presence meant they would no longer enjoy an existence where they had everything provided and nothing to worry about. Now in a world where sin and death had entered, they would need something else, which would actually be God’s divine protection, just symbolized by protective skins. God’s plan was for them to procreate, thus he protects them, symbolically with skins.