You should be able to take the right high school prerequisites if you're looking for the right ones.
Before you can take nursing classes toward a RN / BSN, you're going to need a ton of Gen-eds which I'm pretty sure you can take. A few of the students I tutor have done so.
I recommend that you speak to an advisor at your school about this because I think you're a little confused about how
to become a nurse.
If you go the LPN/bridge route, it's going to take you longer & cost you more money. If you tailor your Gen-Eds to suit a nursing program you can start after high school, then you're looking at subjects like (but not limited to):
- Anatomy & physiology 1 & 2
- DIET1030 or equivalent (Principles of nutrition)
- English composition 1, 2, & a literature credit
- Math1530 - probability & statistics (or equivalent)
- POSSIBLE: Pre-calc, algebra II, or Algebra & trigenometry
- plus many more...~
To get an exact list of subjects you're going to want to speak to a counselor/adviser at your school and maybe even the college you wish to attend after.
It's highly unlikely that you'll be able to go straight from high school to a nursing program, just because of the amount of Gen Eds that you will need to get out of the way - this is normal
To answer your question about the difference between LPN and RN though - pay grade, scope of practice to name two.