California Community college transfer applicants do get priority over UC to UC transfers, CSU to UC transfers, 4 year in-state privates and finally OOS transfers (lowest priority).
If costs are an issue, I would finish off your Freshman year at your current college and start taking courses at a California community college in the summer.
6 UC campuses offer TAG (Transfer Admission Guarantee) which guarantees admission to one of the 6 participating campuses (UCSB is one but not UCSD) if you meet all the course and GPA requirements. You have to be attending a California CC to TAG to the UC’s.
The TAG application needs to be submitted in September (year prior to matriculation).
https://admission.universityofcalifornia.edu/_assets/files/transfer-requirements/tag-matrix.pdf
Best of luck.