Anything to improve on for UC's?

Im a sophomore in Highschool right now and I was wondering if there was anything i can improve on or get to help me get into a good UC

Grades:
Freshman year 4.0/4.0
Sophomore year: 3.5 ._. I got a B and a C in algebra 2 H and chemistry H/ still working on it but 3.8?
(my school doesnt go above a 4)

EC
Jv basketball (2 years) Team Captain and MVP twice
Red Cross(trying out for cabinet)
MUN
FBLA
Speech and Debate
going to a Leadership Development camp
Internship with Red Cross
VBS (vacation bible school) volunteer for church
Staff Writer for school newspaper

PSAT:1100

Majors im thinking about
Biochemistry
Biomedical Sciences
Journalism?
something in the Med department

IS there anything I can do or anything i need to get like

for ACT Score

gpas for junior year
volunteering at a hospital?

PLEASE HELP ;( the schools I def would love to get into are UCSB UCI UCSD UCLA and CAL
Thanks!!