If you have time...
The very best thing you can do for yourself is take a University general chemistry course.
It will teach you acid/base, osmosis, diffusion, ideal gas law, (which is dead useful for volume of distribution in pharm) and most importantly, conversion factors.
Other classes that are beneficial are Intro to bio for science majors and A&P.
The most important thing to remember is paramedic class is not about what goes on in the street. It is school and what is important in school is all that book stuff.
If you ever once read part of a chapter and think "I don't need to know this" you have taken the first step towards failure.
Drug abusers can start IVs
Lay people can do CPR
First responders "immobilize" patients
I have seen 7 year old children of instructors intubate Fred the head to NR standards.
Skills make up a very small part of what you need. Don't get too focused on them.
If you don't learn what you need to pass the book test, what "matters in the field" will not matter, because you won't be in it.
Always ask "why" and never be satisfied with the answer.