It depends on your high school, and what kinds of classes or programs it offers.  It may also depend on where you plan to go to nursing school.  It is not too early to investigate places you might want to attend, and find out about their admission requirements.  That will help you and your guidance counselor plan your high school course.

In broad terms, if your high school has a college prep program I would take that.  Take all the science courses you can, and get at least through Alegbra II.  Make sure you take plenty of English too--with a focus on reading and how to interpret what you read.  Why is this important?  Because good reading comprehension and writing skills will make it easier for you to understand college level science textbooks.  If you ignore your reading skills, and are unable to understand your textbooks (which are expensive, so you don't want to throw good money away on a book you can't understand).

If you plan on going to the local CC, check out the program and see if they either require CNA certification or if it gets you ranking points in their admission process.  Then see if your high school offers health courses that will get you certified as credit towards your high school graduation.

If your school has a program that will let you take courses at the local CC, then do so as soon as you are eligible.  Anything you can do to get college credits will prepare you for nursing school, and prepare you for college level work.

I taught at a medical magnet high school. I was a clinical instructor but I can tell you most of my students (juniors) had taken, or were taking, AP Chemistry, AP Biology, Calculus and AP English. Don't forget the English - that is a flunk out course in college because everybody thinks it's 3 easy hours. It certainly is not and has everything to do with writing papers in the proper format.