Please help me im STRESSING OUT !?!?!?!?!?!!?!?!?!? 10points to best answer?

ok so i have a school camp in 4 days and there's a guy i like who i really want to empress (hair/ clothes wise) now its a school camp so that means no skirts and only stud earrings and no make-up and no spaghetti strap/ normal strap tops and tops have to have a collar ( im wearing strap tops with no collar weaver they like it or not :) ) so what are some really cute sexy clothes i can wear not a fan of skirts btw we are going to Canberra and it will be FREEZING so i was thinking of getting some opaces they are a really thick type of stocking like leggings and i could wear them under denim shorts with a loose fitting strap colourful top from supre would that be cute? i really want to impress this guy im 80 pounds and 13 i have long legs! long blonde hair ( kinda medium but long compared to my friends) and im kinda tanned and not in adult bra's yet but im close :) any ideas are helpful thanks :) xx