I don't have many big memories of highschool. I went to a sports academy from 8-10, then moved out to the regular school for grades 11-12.
The sports academy is a mini-school. It's a specialized program of students that is hosted within the larger high school. We got our own wing, and the school had a total of 90 students (30 per grade) and 4 teachers (1 French, 1 Socials/English, 1 Math, 1 Science). The 30 students in your grade are your classmates for every class until you graduate the program, so you'll get to know the same people all year for 3 years straight. It's a good opportunity to make close friends, but also really easy to find someone you dislike and want to leave the program ASAP because you're stuck with them every day, all year. We had the basic classes plus electives that we could choose at the beginning of the term. There was usually a camp requirement at the beginning and at the end of the school year. P.E. was the special class since it was an outdoor-education school. We usually had P.E. outside of school, at bowling alleys, skating rinks, swimming pools, horse-back riding, snow-shoeing, skiing, snowboard, etc. We paid about $900 yearly for these activities, but there were stay-at-school P.E. options if you wanted to save money since activities were pay-per, and you could get your money returned if it the deposit wasn't used up by the end of the year.
High school in grade 11 & 12 was pretty chill. I had my friends from grade 8-10 in the academy move out into the larger school with me so I had people to be with. I also got to know a few more people due to similar interests, friends of friends, and simply by proximity in classes. We had an advisory class, or home room class before lunch that was meant for students to just have free time to work on their own work, learn about life skills, hang out, and just chat with the home room teacher. Technically, advisory class was our "home base". I liked my advisory class: A lot of my Japanese classmates were in there with me, and my advisory teacher was my Japanese teacher. We would often just watch anime on the projector screen during advisory since the teacher was pretty lax. Eventually, I ended up playing a TCG game with some of the guys, so we grew pretty close over the course of two years.
Grades were not hard to achieve in HS grade 11/12. What used to be fairly hard to get an A in minischool was nearly effortless in high school. My province's standards were 86% to get an A, so people would often ask, "Did you get like, an 86 A, or like an 'over 90' A?"
As for the diversity in my school, it was pretty high. About 90 percent of the school was Asian. Breakdown: 60% Chinese (Hong Kong, Mainland, Taiwan), 20% Phillipeno, and 10% Indian/South-Asian. There were a couple miscellaneous ethnicities mixed in there as well, like Japanese or Vietnamese. Out of the about 900 students at my school, there were about... 15 "white" students? I was friends with only one, and another who was more Russian than English. Washrooms were usually confusing for transfer or exchange students, since there was a clique of "tomboys" who looked very, very masculine, but you would see them in the girls' washroom. There was also this one Phillipeno student I wasn't sure was male or female, but everyone loved him/her because they were sassy diva/on fire and on the dance team.
Teachers were on the young side: Most of them were in their late twenties or early thirties. A few were in their forties. Parents would often mistake the young female teachers for students because they dressed young. Most were inviting and helpful, hosting Mario Kart parties in their class at lunch, letting you use the computer lab to play games at lunch, or just opened their classroom for students to work on stuff (like the home-ec room).
This was my high school experience from grades 8-12 from 2007-2012 on the Canadian west-coast, in a city with very high percentage of visible minorities.