You can coast in this class but spend extra time doing an online statistics class. You can do an online econ class. You can study astronomy, physiology, any one of 100 topics not taught in a HS. Why are you fixated on taking calculus early? There are so many areas you could be exploring right now.
And making sloppy mistakes now seems trivial towards your life plan (whatever that may be). But oncologists prescribe an exact dose- a sloppy mistake could kill the patient. A civil engineer calculates the exact load on a retaining wall- not a “kinda/sorta” load. An aerospace engineer designs a braking system exactly calibrated to the weight of a fully loaded aircraft- without a “sloppy” error.
This is something you can fix. Now.