Linda, I'll see you at Warwick! I have an AAB offer to do philosophy there this September so as long as I get the grades that's where I'll be going!
As for having studied philosophy before... I do philosophy A level but apparantly it's not a huge help for degree level. I think it helps you find out how much you're actually interested in the subject to study it before, and to let yourself know what you're letting yourself in for, but as long as you do plenty of reading beforehand I think it'll be fine. As has already been said, most people applying wont have studied it before, so best of luck!