Experience the difference! Whatever you are used to, your new school abroad will definitely be something else. A new language in a new cultural environment is so exciting to learn and this knowledge will be a great asset for you later in life.
Of course you will experience a lot of new things. You might notice another kind of discipline and rule system, maybe a different dress code or another way of addressing your teacher. Before you know it you have adapted to the new things and at the same time you have grown as a person. Your life will be so much more than school. You will have lots of free time with activities, sports and outings that will further advance your development on foreign ground. No question about it. Your high school year abroad will mean the world to you.