If you’re a pre-med, then you need general chemistry, organic chemistry and biochemistry, plus coursework in biology, physics, calculus, math-based statistics or biostatistics, psychology, sociology, and 2 semesters of college composition. Many medical schools also recommend taking genetics, human anatomy, and human physiology.
But with multiple failed classes, you have a really, really long way to go fix your GPA. Successful med school applicants need a GPA>3.7. Medical schools do not permit grade replacement. If you retake a class, both the original class grade and the re-take grade will be included in all GPA calculations.
(BTW, medical schools do not accept online coursework to fulfill admission requirements so if you’re taking online classes, that won’t work. Taking your pre-reqs at a community college has problems too.)
You should make an appointment with the academic support center to your college to find out why you are doing so poorly in your classes.