These are both great schools for computer science (and for a long list of other majors as well).
You do not need to go to UC Berkeley. If you want to get a master’s degree at some point in the future, UCB will still be there.
If I had a choice between UF for free, versus full cost out of state at UCB, I think that I would go for UF for undergrad, and then get a couple of years work experience, and then think about whether I wanted to spend the big bucks for a master’s degree at UCB (or at Stanford or somewhere else).