There are only references. There is also a guy and a girl who make out in a closet, but his arm is hiding their faces. There is no graphic nudity.

in a locker room scene, a few males seen shirtless for about 15 seconds

Season two has some sexual content.

One of the main male characterz is video calling another male character. The male character on the call isn't wearing shirt.

There is a scene where a girl is found bound and gagged, with only her bra and panties on.

a girl cuts her arm with scissors

Violence is frequent but not showed in so much detail so it may not be noticed. It includes people fighting, which leads to blood or people going to the hospital. A video of a person falling down from a balcony and then dying is shown.

Frequent profanity with many uses of fuck and milder language

Frequent partying with alcohol and implied drug use

A few fights with one in particular shown graphically. A recording of someone's death is seen. A girl is shown cutting herself and alludes to frequent self harm.

There's scenes of Bullying which may upset some viewers.

There is also a scene where 2 boys are found buried alive.