For the UC’s, Freshman year does not count in the UC GPA calculation, only 10-11th grades. 3 C’s will probably hurt your chances at all but UCSC but you never know unless you apply. There are still many great schools where you have a good chance for an acceptance and you still have another year to turn around your GPA. Continue taking a rigorous course schedule, but make sure you get A’s in these classes. Keep with your EC’s.
End of Junior year, calculate your UC GPA: http://rogerhub.com/gpa-calculator-uc/ along with SLO GPA (which does include 9th grades), post your test scores and EC’s and you will get a more informed chancing for these schools.
You can also look at the UC or school websites for the average UC GPA/SAT/ACT scores and what you need to be competitive. Averages from last years Freshman Class:
SCHOOL/GPA/ACT/SAT
UCSC: 3.82/1782/26
UCI: 4.05/1867/27
UCSD: 4.13/2018/30
UCLA: 4.17/2067/30
UCB: 4.18/2971/31