Don't ever change that way you look for a guy. Don't ever change who you are for a guy. Be yourself. If you turn into an attention-getter, then you will attract the wrong guy, and I'm 95% sure, you don't want that. Are you crazy? Be crazy. Are you funny? Be funny. It's not all about looks. Guys who only care about a girl's personality, are the good guys who will stay with you no matter what. Guys who only care about a girl's looks, are the ones who don't stay with you for that long. I learned that from what I have seen and from personal experience.
Wear yoga pants or leggings with a looser sweater. Boys really like tight pants for reasons... Just remember, keep it CLASSY. Don't show too much, that's going to give off the wrong impression. Wear what makes you feel confident.