I would recommend taking as many AP/advanced level classes that you feel comfortable taking and that are offered in the math and science program at your school. Depending on your interests, chemistry, physics, and calculus are some typical courses that would be useful in most engineering disciplines and I would encourage you to explore these subjects if you are given the opportunity. I also think that exposure to computer science and programming would be helpful if your school offers any courses in this area. In terms of getting into colleges of your choice, admissions committees often look for students who are willing to push themselves and try harder classes as it is a good indication that you would succeed at a college level.
Hope this helps and best of luck!