https://www.universityofcalifornia.edu/infocenter/fall-enrollment-glance can give some UC numbers on transfers versus frosh (entry level) versus various characteristics (e.g. parent education, ethnicity). Unfortunately, the most direct characteristics for this question (entry level and Pell grant) are not available together in the same tab.
Students with non-college-educated parents are more likely to be Pell grant students and transfers compared to students with college educated parents.