G. Mark’s Answer
The typical answer you'll get is STEM-related classes. Science, Technology, Chemistry, advanced Mathematics. But I'll let you in on something that's served me in good stead in my career. Don't limit yourself. The most creative engineers and the ones with the most patents that they got personally (rather than having been associated with some group that added their name to a patent they had little to actually do with, such as being the person who took notes during the meetings :-) ) were creative in many areas outside engineering. One example is that if you develop good writing skills, you'll be more successful in communicating your ideas, and that is essential to working on most teams. The quickest way to achieve your requirements in STEM classes is to talk to a counselor familiar with engineering and the sciences. They'll be able to point you to the exact curriculum and set of courses offered in your high school. They'll also be more likely to point you to opportunities for extracurricular activities and internships, which are wonder ways to get a future job that you'll love.