If you are talking about the bscn Ryerson-GBC program, I have a clue on how it is in first semester because I was in the program in 2013. I am pretty sure still similar but correct me if I am wrong.
First, your grades are good! Just keep your overall average 85%+, but aim for 90% average because it's becoming more competitive every year. I think it's top six 4U courses from high school.
Since you'll be attending GBC for the first two years, you'll be choosing blocks, which is a premade schedule.. You'll have 6 mandatory courses + 1 electives.
As for difficulty, my friends did say the first two years were hell and they all complained of Pathophysiology. Time management is key! In first semester, Nutrition course (FNN111) and introduction to psychology (PSY102) were breeze. Nursing courses were challenging. From what I remember, you have something going on every week - whether it is test, assignment, quizzes, demonstration (graded) for health assessment, presentation, group work.
As soon as you get an offer of admission, I highly recommend going through anatomy and physiology. Just check which textbook they are using for this year and use it. Anatomy is not hard but it's a lot of information.
2nd semester will be your first clinical placement!
Please newly graduates let me know if anything changed since 2013.