When you get to a UC (or a private school, like USC), you start with a fresh GPA.
Not sure how it works with graduate school but you’ll obviously report all your grades. I would assume they’d put the most weight on your actual UC GPA, not community college. I don’t know for sure though.
I think it’s something you shouldn’t really be worrying about now as it’s not only far away but entirely out of your hands. Just focus on getting the best grades you can now, successfully transferring, and doing well wherever you transfer to.