I guess from your post that you are presently a student somewhere on the West coast of Wales, UK.
The plan to spend your 'gap year' sailing in the Pacific needs a little filling out :-
To start with, you will need to think through and define the purpose; you will need a budget plan; a starting point and a destination; the type of sailboat; will you be unpaid crew or will you pay to charter or will you be the skipper on your own boat.
As your 'gap year' is still a year away. Good advice would be a reason to research libraries, the internet, yacht clubs and sailing schools in your area etc.. - remembering that sailing an offshore sailboat requires more than knowledge and the experience of sailing, but the ability to maintain, diagnose and repair if possible, all equipment and systems aboard the modern sailboat.