I got the hang of the grading system my sophomore year, generally speaking, you kind of just have to "attempt" working, or at least make it look like you are, and things will be real easy. Granted, my gpa is shit, I didn't care for high grades, and I made sure all my teachers knew it (D stands for Diploma!).
Highschool was a hell of a lot easier for me socially since I can be quite the introvert while I'm in school. Popularity was pretty much thrown out the window and everybody was just more chilled out, thank god for drugs. Ironically, my school had the highest suicide rate in either my county or state, freshman year it was one of my teachers, sophomore year it was one of my buddies, and about one per year every year afterwards.
The relaxed atmosphere seemed to be more prominent in the more populated schools, I've been to two small highschools for parts of some school years and there was a hell of a lot more drama, or perhaps it was more compact drama... Don't know.
And the best part of course would be the brawls, there will be lots, at least if your school is anything like mine was. They're like MMA for highly uncoordinated individuals. Very short lived but very entertaining.
If I could tell the past me something, it would be to get a good sleep schedule, eat your veggies, buy as many pens as you can afford, there's an infinite amount of possible outcomes to every situation, half of which don't end the way you really hope they won't, and to just chill.
I've never really liked shark week.