A girl has her shirt accidentally torn away after being asked to flash a boy and you briefly see female frontal nudity

You see a cartoon penis in the intro.

A boy in a lady's body enters the lady showers, and you see breasts clearly in several shots as well as butts and several full frontal shots. In some versions of the film, a steam effect is used to obscure the nudity.

We see some partial nude men, briefly. One man has bat on his penis (which hides it) and he moves that bat as if it's his penis.

A girl gets her pubes waxed, though her genitals are not seen, the wax-sheet covers them

We briefly see a girl's buttocks

A man is naked twice in men showers, only his buttocks are visible (other men are partially nude)

A man talks to a woman about having erections in the morning.

Some mild sporting violence.

A man tries to break (what?) a girl. But a guy comes to protect her by knocking the guy down.

A character kicks a cat, which was sticking its claws in the character's foot.

Some mild coarse language like bitch.

Some sexual references including mention of breasts, erection, pubes and masturbation.

A scene where a lot of teenage men drink a lot beer (drinking game). They also put some type of drug in their glasses.

None.