UCD vs UCSB vs UCI vs UCSC vs Cal Poly SLO

Hello! I’m currently stuck between choosing these colleges. I got into UCSB for pre-bio, UCI for biological sciences, UCSC for computer engineering, waitlisted at UCD for biological sciences, and Cal Poly SLO for biological sciences. I am hoping to study somewhere in the science or technology field, but I’m not really sure about what I want to major in from those fields. Based on my interests, which college do you guys think will be best for me? I was also offered the UCSB Promise Scholarship which is also pretty attractive, but I’m kind of turned away by UCSB’s party reputation. Also how hard would it be for me to change majors from biology to say computer engineering or just other majors in the same college of Letters and Science.