Pre-med is not a major it is an intention. Taking science and math in High school will prepare for the courses needed to do well in college, but there are not particular courses in HS you should take other than to challenge yourself and to fulfill HS graduation requirements and also College admission requirements. You can major in any subject in college but will need to take the Medical school course requirements to apply.
First, it is important to remember that, regardless of what major you ultimately choose, there are core courses that most medical schools require you take:
• two semesters of biology with laboratory (up to four semesters at some schools)
• two semesters of inorganic chemistry with laboratory
• two semesters of organic chemistry with laboratory
• two semesters of math, at least one in calculus
• two semesters of physics with laboratory
• two semesters of English and/or writing