Since you're interested in physics, it's a good idea to take lots of
math early on. That opens up many physics courses for you later.
Certainly you should take several semesters of calculus as soon as you
can, then probably linear algebra and complex analysis. It also helps
to take an introductory physics course in secondary school. In college,
the actual physics courses will not be hard to find, with the beginning
sequence usually laid out in an organized way.
Having a chance to try actual research is especially important,
and may take more effort to set up. To get ready for it, you should
look for lab courses, especially in electronics, and also learn some
computer programming. If you have a chance, try to pick a college where
there are opportunities for undergraduates to do research.
Careers in physics include research at government or industrial
labs, teaching at college or secondary school, combined research and
teaching at universities, and physics applications in industry. For
example, many physicists are employed developing new types of magnetic
disk drives for computers. Since physics is so generally applicable,
lots of people start with some pure physics training then branch out
into biological or engineering fields.
(published on 10/22/2007)