Do not waste your time going to CSULB just so you can transfer to a UC a couple years later. Not only is it a bit difficult to transfer from a CS to a UC bit it will also cost you a lot more money than transferring from a CC. The cost of a unit at a Community College is about 50 dollars, I have no idea what the cost of tuition is at a CS but I doubt it’s lower than 50 dollars per unit.
I am not sure how it works or even if it’s possible for you to transfer to a UC as a sophomore but my two cents is to go to a CC for two years and put in your transfer.