@Empireapple eww. what. Thats completely not true. There is still a invisible dress code at a university, unless you don’t want to fit in.
note to OP: TBH. a “preppy” style is completely dependent on how you can style your clothes. You don’t need to load your closet with vineyard vines, patagonia, and north face clothes. A few staple items from them and you’re set. Overall you just need to dress modest, fitting, modern, and clean.
Always a big note: if you can’t afford the big brands, don’t buy them. You can tell when people are trying to fit in and it’ll just makes you look worse.