If you need specific help on particular homework problem or concepts, you can always post questions here. We are pretty responsive.
If you need more extensive and regular supplementary instruction, I would first contact your teaching assistant if you have one, or, if your professor is approachable, contact them... although I don't know how that would work in the era of Covid. Most large universities also have tutoring services. I don't have much familiarity with the online tutoring services, so YMMV.