The highschool atmosphere will probably be a little different and the homework load will increase a little but other than that it'll just be like going from sixth to seventh grade or fourth to fifth grade or whatever because it's not like they're gonna be teaching you college material stuff, it'll just be another step up and hopefully your eighth grade teachers have taught you what you need to know to succeed in the next grade
Whatever grade you're in is the hardest, because you've finished the last and have to work toward the next. Just keep up with your homework that's the easiest part to fail at, and don't miss classes and be sure to stay involved in the lesson, even if you're wrong .... Trying and being there ALWAYS looks good to your teachers, and after all they're the ones grading your efforts. Right?
Freshman year and sophomore year. The main reason why its these two grades is because when you first enter high school, you don't know wtf your supposed to do, who to go to or who to hang out with and grades are hard to keep up with because you think you could own your grades. Sophomore year is tough because your just now getting the hang of everything and then you get new material to study and new people in your class so it becomes tougher as you go.
11th and 12th Junior year is hard becasue u are getting ready to be a senior next year and everything has to be in its place. 12th grade becasue teachers expect so muc of u and u will leave people behind to have a new life in college. Dont be afraid , freshmen year is the easiest, sophmore is the least academically pressuring, it's pretty smooth your first 2 years, but once you hit junior year, it gets challenging.
Freshman year(9th) and Junior year(11th) Those are the hardest years, and the years that count the most compared to sophomore and senior year, you screw up those years, it pretty much guarantees you're not gonna walk with your class a graduation. trust me, I know people who did, and didn't graduate with their class and regretted it.
The first when you have to get use to all the new things there and the last one when you have to put so much efforts to graduate with your classmates if you don't want to feel like a fool. So my advise is if you want everything to go smooth till the last year with graduation you should show persistence in learning. Do an exchange program if you can, it is worth it!