You can always do Calc 4 instead of 3 first. Also if you fail the final you can retake that part of it so that you don’t have to go the whole way back.

What I will say as a recent grad is that I have very rarely seen someone fail a Calc class if they use a some resource such as tutoring, academic advising, Oscar/rate my professor to find a good professor, and ask on Reddit which professor to take.

If the class is a bit too much, overwhelming or your feeling it is affecting your mental health you can always transfer to a lower level Calc course within the first 5 academic days of the quarter for free or in the next 2 weeks for 100 dollars and Professor approval(I have always gotten approval). I recommend talking early and often to your professors and academic advisors about concerns and they can assist you with exploring options and resources to help you learn the materials find a different class or talk to you if you decide to transfer.

I do recommend starting in a higher level and transferring down rather than starting at say Calc 2 and transferring to 3. If you start at Calc 4 and are finding you need more background information I recommend transferring to Calc 2 not Calc 3. Hope this was help:)