Hello! My first year was alright, but by the end of the year I was pretty exhausted (mostly because I didn't enjoy the subjects I took in semester 3 + trimesters in general). I'm excited to do more specialised subjects though for second year :)
It's pretty uncommon that anything changes but it does happen. It's just a clerical check though, basically seeing if the computer mis-scaned a question or missed marks, rather than a thorough check of your answers. I did it for bio and Chem last year to check my raw mark, and nothing changed