the college should have a pamphlet or some such about what courses are required to complete the nursing program at that college. it will include pre-req's and core classes.
as RN2b stated, anatomy, physiology, micro, and organic chemistry are some of the classes needed. also stuff like philosophy, psychology, sociology.
some of those classes have pre-req's of their own. for example, at my school must take either high school chem or college level intro to chem before you can take organic chemistry.
i'm assuming that the classes you take at the college will apply towards high school credits, right? i've had classes with several students doing that.
my advice would be to get your english comp I and II out of the way. since you will probably need organic chemistry for the nursing program, i would get the intro to chem out of the way.
some anatomy and physiology classes require basic biology or human biology as a pre-req. if this is the case for your school, get them out of the way too.
as for the math, don't sweat it. the actual math pre-req classes you take will be harder than the math you need in the nursing program. our school accepts algebra and then a medical math class, usually one quarter/semester of each. this tends to include things like simple formulas, conversions, measurements, etc. some knowledge of fractions would be helpful. and of course, the basics such as multiplication and division.
good luck to you