I did a breastfeeding class when I was pregnant with my 2nd because my first I had no idea what I was doing and my nipples got butchered, which took 2 weeks to heal. I didn't want to do that again.
So 2nd baby she fed within an hour after birth, and I knew how to get on her on. and what a proper latch was etc. to keep my nipples intact. I had one little blister on one side, which I believe occurred when I was being stitched up. It was a bit hard to focus on both of those things at once. Milk came in on day 2.
Third baby, no nipple damage at all, milk came in on day 2.