How does the application process really work?

I am an international student from China but I have been studying in the US for 4 years. It seems so difficult to find helpful information online about the application process of University of Toronto, and I really want to know how does that work. I have started the 105D application days ago but I didn’t see anything on my application that mentioned the adademic transcript or test scores though.
And I also want to know, do they just look at 11 and 12th grade courses? I did very well the last two years compared to the first two so I hope it will boost up my chance?
I have a 3.8 UW GPA and 4.2 WGPA last year with 3 APs, and this year I will have a UW of 3.6 and W 4.4 with 4 APs and 1 honor. I have 1420 on SAT, 780 on SAT Math 2 and 740 on SAT 2 Chemistry. Do I have a good chance? Thank you so much!

U of T doesn’t look at 9th or 10th grade courses, just 11th and 12th.

Your stats look fine, but the likelihood of being admitted depends on which program you are applying for. The document checklist is on this page: http://www.future.utoronto.ca/apply/applying#required-documents