Rankings are a game to sell magazines; they don’t measure anything that is real in the level of detail between schools that you are assuming. Nor is it wise to rely on recs from current undergrads about their school; for obvious reasons they are hardly neutral commentators.
In fact any college in the country offers the lower-division science and math tested on the MCAT. Whether you work work for good grades, get to know some profs so you get strong recs, take part in appropriate ECs, and develop compelling essays is up to you.
Your 2 choices are equivalent, and the data shows it. For the years leading up to 2010 (which is the latest they have online) UCSD had an acceptance rate in the low 40s according to http://career.ucsd.edu/undergraduates/thinking-about-grad-school/pre-medical-data.html and UCSB reports the same for the years 2011-2015 at http://www.duels.ucsb.edu/professional/health/med It’s hard to find evidence for “way better” here.
With 2 equivalent schools, the difference you’ll experience really comes down to your preferences in college. One is largely a commuter school near a great city, one is a college where everyone lives on/adjacent but in a more isolated area.
Spend some time reviewing what it takes to get into med school by reading thru the very informative https://www.rhodes.edu/sites/default/files/PreMed_Essentials.pdf. There is also a good handbook at https://www.amherst.edu/campuslife/careers/gradstudy/health/guide and no doubt many other websites, as well as books. One thing you’ll discover, BTW, is that research is no longer the sine qua non it was 20 years ago but that exposure to medicine is. Anyone touting their “number of research opportunities” is apparently unaware of this.
One special concern for you is that you come from a CC. That does not prevent you from getting into med school, but they are leery of kids that took the handful of required prep classes at a CC. As a Bio major you will be taking upper-division bio, of course, but you ought to talk with a premed advisor about more math and about another course in Chem if you took o-chem at your CC since that is a class they really look at in me admissions.