There are two ways to study Computer Science (CS) at UC Berkeley:
Be admitted to the Electrical Engineering & Computer Sciences (EECS) major in the College of Engineering (COE) as a freshman. Admission to the COE, however, is extremely competitive. This option leads to a Bachelor of Science (BS) degree. This path is appropriate for people who want an engineering education.
Enter the College of Letters & Science (L&S) and, after successful completion of the courses required to declare with the minimum grade point average (GPA), petition to be admitted to the L&S Computer Science major. This path is appropriate for people who are interested in a broader education in the sciences and arts (such as double majoring in other L&S fields), and/or are not sure at the time of application that they can gain admission to EECS. This option leads to a Bachelor of Arts (BA) degree.
There is no difference in the CS course content between the BS and BA programs. The difference is in what else you take: mainly engineering, or mainly humanities and social sciences. In particular, an interest in hardware suggests the EECS route; an interest in double majoring (for example, in math or cognitive science) suggests the L&S route.
Here is the course requirements for each path: https://eecs.berkeley.edu/resources/undergrads/cs/degree-reqs-upperdiv
GPA matters at your community college if the course is UC transferable, it will be included in your HS GPA if you are dual enrolled so getting good grades in both classes can impact your chances. Your CC GPA will however not transfer. You will start fresh at UCB with a new GPA.