Remedial calc 1 at CC?

I’m a sophomore in high school and I failed my calculus class… whoops…
Basically my teacher only gave six tests this year, I did fairly ok on all of them until the 4th test which I bombed along with the rest of the class. Teacher didn’t curve or offer a retest so most of us(especially me) were frantically trying to do damage control on our grade. Most of the kids were better off than me, lots of kids get over 100 on most of the tests but I got low 90s/high 80s on the first 3 tests. Now I learned that most of the kids in the class get copies of his old tests from upperclassmen and alumni, which he doesn’t change from year to year, so that explains it.
I ended up getting a 97 on his definite integrals test easily, but I conveniently had a panic attack during the most recent one and answered only 6 questions(pressure to bring my grade up may have contributed). Teacher emailed my dad and said I got in the 20s. Now I need an 100 on the final to pass the class and I know I can’t get that good of a score.
I know people at my school have dropped out of a class because there was a very low chance of passing, so I’m trying to get the admin to give me an incomplete and let me remediate the class over the summer. This course isn’t offered during the district’s summer school so I have 2 options: retake it during the year (would mean I’d be behind on math credits so I’d have to double up on calc BC and stats senior year) or take calc 1 at CC this summer to replace it. Looks like the latter is the best plan, so how am I supposed to go about this? Do community colleges usually require permission from your principal? Also, since I recieved an A in precalculus/trig freshman year, would they just let me in the calculus course or would I have to take a placement test?