Need help from any people in University of Waterloo?

i am in grade 10 (goin to grd 11) and i am in the IB program. i am interested to attend a course at waterloo under engineering or some type of medical course (sciences). ive already checked on the official website but i'd like to get answers from some people who have already made it into waterloo. what things did you do to get in? in particular, what marks did you get? whats an average that will make me have a good chance of getting in. can i get in with mid 80's or do i need to only get 90's. and also, id apreciate if you told me what ur averages were when u were accepted and marks in math/science and english. what should i aim for? cost isnt the issue but instead of just knowing the minimum average to apply, id like to hear from a person who already has been accepted. this does not only go to university of waterloo students, but also, people from McMasters of UFT. thanks!