Learn everything there is to know about clothing (what matches, what colors go with seasons, what looks good on certain people and brings out there features, clothing brands, clothing types, what materials and patterns work, ect.) Also begin a sketch book or portfolio of clothes you like or want to design. Then do really well in schooling and look around at some art schools. See what degrees you need to get in and do it. Also remember it's one baby step at a time for your goal. Good luck!
