The total number of classes is going to vary by high school. Does your high school have 8 regular periods in the school day?
Our high school has 6 regular periods in the school day, which leaves limited space for electives. My kids both take orchestra during the school day, so every year they have English, math, social studies, science, foreign language, and orchestra. They don’t have any space in their schedules to double up on English or science, or to add another elective such as CS, robotics, fine art, etc.