The school you will attend during your Italian stay will probably be quite different from your own. Italian High School lasts five years and attendance is generally mandatory 6 days a week, only in the morning. The school year starts in the middle of September and ends at the beginning of June.
There are different types of High School (classical, scientific, linguistic, technical), but several subjects are common to all courses, such as Italian language and literature, English grammar and literature, Maths, PE, History and Science. Other subjects will be more specific according to the type of school.
Attending an Italian High School, even if for a short term, will give you an idea on how a different school system works, the opportunity to learn the language and improve your knowledge, and the chance to meet people of your age, with whom you can build a lifelong friendship!