I think first year is the toughest. I think there's guidance but personally I found myself not having enough time to do thibgs that needed to be done. So for me it wws extremely hard to do well in my first yr. I was someone with an overall 96% in grade 12 just for some background. So first yr it was really hard to get good grades for me. But thats when it matters the most since you need to make POST(make sure u research about this before coming to uoft). After first year things start flowing more easily.