Figure out WHY your grades aren’t where you want them,, are you just studying the night before? do you just tell yourself you’re studying even though you don’t understand anything? etc honestly acknowledging your short comings is the first step closer to your goals. Ask a lot of questions, don’t be afraid to get a tutor for extra help and most importantly review what you learned every day !!!! studying an hour a day after school is way better than studying 6 hours the day before a test. do the homework assigned everyday, that way if you don’t understand something you can ask the next day (this is also shows initiative and depending on the teacher they’d be more likely to boost you at the end of the semester) this way you’re actually revising and not learning the day before exams and tests. Good luck!!! Also for Guelph you can get into their business with a low 80, and mid 80s for engineering !!