Your primary focus should be your GPA, and completing all prerequisites for your major or other requirements. Which school? Berkeley?
Get involved in clubs or whatnot if you want to. It isn’t necessary. Keep a light course load and do as best you can. Your major is very competitive - it is difficult to get into the top schools with your major, even as a transfer. Many technical majors like CS have to spend 3 years at CC completing all of the requirements. Check assist.org - put in your CC and a specific UC campus and your major, and you should see which classes you’ll have to take.
They want to see that you are able to do well in college-level classes, and complete all (or as many as you possibly can) prereq’s and general education requirements.