That pictures of models/celebrities in magazines are fake.
That magazines like Closer and Heat are toxic and only serve to make you feel bad about yourself and mean about others.
That it's pretty easy to look amazing if you employ a team of stylists, hairdressers, beauticians and make-up artists. 99.9% of the population don't, so don't compare yourself to celebrities.
That confidence comes from within, and even if you had better clothes/shoes/hair/teeth/breasts/legs, you'd still be you. So work on your inner self way more than your outer self.
Females young and old get judged a lot. Be prepared for it, and don't do it to others. We're our own worst enemies.
That porn sex is not real sex.
That they, and only they, decide how intimate they want to be in a relationship. It's easy to lose your virginity, but not so easy to find it again.
That although women now can "have it all" (the fabulous job, the amazing wardrobe, the immaculate house, the perfect body), it doesn't mean you have to, should expect/want to, or would be happy if you did.
That a sense of humour in yourself, your friends and your partner is essential.