I am currently attending CCC and planning to apply to UC as a transfer applicant this fall. 
I know that there is a minimum credit requirement (90 quarter unit). My question is: Do more credits make applicant more competitive? (ex. applicant with 100 credits vs 90 credits?) OR do the amount of credits/units not matter at all as long as I meet the 90 credits requirement?
Thank you!!
doesn’t matter as long as you finish all your requirements. Some majors, particularly the sciences, require much more units than the 90 quarter or 60 semester unit minimum.
The only way it really benefits is if the courses are recommended for the major.
Anecdotally, it seems to help. UCLA used to post average units for admitted students, and many of them were much higher than the minimum of 90 (60 semester, 90 quarter). Most competitive majors had 105+. UCLA econ was somewhere around there, and it has a pretty low requirement for lower div major classes.
High units from CCs may appear to be advantageous, but it really may be that those with high units have covered more of the subject requirements for their majors and IGETC / general education. Also, CCs may have unit inflation, such as calculus 1 and 2 being 5 units each at some CCs instead of 4 units each.