i’ve lived in California my entire life, until freshman year when I lived out of the country for one year. I came back to finish sophomore and junior year, and now i’m starting senior year here too. The UC app asks you to clarify whether you’ve been at a California high school for 3+ years so i’m Confused 
Would that make me an international applicant/out of state so my regular fees would be 60k ???
as long as you attend Sr year in CA - you should be set. You still need to meet the admission requirements and have competitive stats.