Are my ACT scores good enough for UCs?

those are pretty good scores. u should be fine. but remember that the admissions process is more complex than just numbers. if you're trying for a school where admission is competitive, they want to know how you as a person will contribute to their community. they look at what you've been doing. they want to see creativity, ambition, commitment. showing off your personality and best qualities is much more important than grades / scores.