Hello Hirama666
You can copy an existing school to a new one, including grade levels. That's all you can do.
As for importing data, there are several modules available to import students, users (staff and parents), timetable.
If there is some data you would like to import and can't find an import module to do so, you can request its development at https://www.rosariosis.org/services/ I will send you a quote.