Dress up in your merch. Your merch can be from your favorite singer, movie, tv-show, cartoon, influencer, idol, anime, and etc. It can be merch from the office or from demon slayer, etc. You are allowed to wear jeans, if they have tears make sure that they are no higher than 5 inches above the knee. Make sure that there are no inappropriate images or profanity. Also, make sure to follow the school dress code.