UK student thinking of going to uni in US?

Ok so I'm 14 and I know it's really early to start thinking about what I want to do with my life but I'm kinda worried about money for the future and if I'll have to start saving up now. I've wanted to move to California almost all my life and over the past half year or so I've decided this is what I want to do with my life. I know it's hard to get a visa to live in the US so I thought it may be easier if I go to uni there. I've looked into it and I'm pretty sure I want to go to UCLA (university of California, Los Angeles) to study art or design. Right now I am in year 9 and for my options I chose Art and Product design and for my core subjects I'm taking Geography and German. I love these subjects and I know I want to take them into my life and career in the future. Tomorrow we are going on a school trip to learn about life choices, careers and what we want to do when we leave school but I'm pretty sure I already know what I want to be doing when I'm 18 - I want to be living in Cali majoring in either art or design. What I want to know is how much will it cost me? How can I pay for it with out getting in too much debt? What can I do to help now? What qualifications do I need? Do I need to start saving up? And what is it like studying in US? Anything else I need to know? Thank you