If you can define which majors you are planning to apply to each campus, I may have some statistical data to help gauge your chances.
Overall you are a wonderful applicant. UCSD has a Math-CS major but the rest of the UC’s and CSU’s do not. If you want to do a double major, then you will need to apply to CS as your primary major. Changing into CS later can be difficult to impossible depending upon campus. Only 3 UC campuses have a CS admit rate above 20% which are Merced, Riverside and Santa Cruz. If you want Data science then not all UC’s or CSU’s offer DS as a major.
Some UC’s admit by major depending upon the College and some do not consider your major choice in their admissions decisions. All CSU’s admit by major.