What first year 3 credit course to take in kin (bsc)

Hi everyone. Right now in my schedule I have all kin classes and 6 credits of science. In total i have 27 credits. However, I want to try to reapply Mcmaster Health Sci or apply med/dental school in the future and they require 30 credits. Since I have kin and sciences, I need a course that won’t damage my GPA.

I have heard that taking the required comp sci course is not recommended for a schedule with already 5 classes and I will have to put lots of time in memorizing in detail of the slides because the professors are not good or the exams are way harder than the material in class. Is this true?

Or should I take the calculus 1 course as it might be hard to get it in my second year?