Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
The original movie "The Craft" (1996) used thousands of snakes, so I watched this hoping for the same, only to find out that it's not a re-make, it's a sequel set 20 or more years in the future. The writers must have realized they had already overdone the snake thing in the first movie, so we only see one or two snakes in this, mostly in a girl's visions, which have a connection to the villain of the story. He's a warlock and a misogynistic men's group leader who writes books about masculinity, named after the biblical ancestor of all men, Adam. Much of the movie is a revenge fantasy with teen girls taking revenge on toxic masculinity and sexual harassment, using witchcraft spells along with powers that we are accustomed to seeing associated with movie superheroes, like lighting fire with fingers and stopping time. I suppose witches and warlocks and wizards were actually the first superheroes, along with the Gods.
Just like "The Craft," this movie is about a new girl in town, Lily, who joins a coven of high school witches. A few minutes into the film we see Lily and her mother drive up to the house where they are going to live which belongs to the mother's fiance, Adam, mentioned above. Lily pulls out a Polaroid camera and takes a picture of the house, then she sees a black-and-white snake on the lawn at her feet, which startles her. Just after that Adam comes out to greet them and nobody mentions the snake, so it seems that this was probably a vision Lily had and not a real snake.
A couple of days later Lily walks into the room of one of her three future stepbrothers where she sees a terrarium housing what looks like the same black-and-white snake she saw on the front lawn. She stares at the snake then sees a vision of a black and white snake crawling in grass, something on fire, and a hand holding a bloody knife against someone's arm. The handle of the knife is made to look like a snake, with the blade extending from the snake's mouth. Later she has a nightmare with the same images in the vision, including the snake. The visions are clearly warnings about her future stepfather, who we find out is a powerful warlock.
One night Lily sees some plaques on a wall with two snakes coiled around a knife. Adam appears and tells her it's his old family crest that goes back centuries. He tells her that snakes are usually considered scary or dangerous but in pagan culture they were symbols of re-birth. Not to mention, phallic symbols. I wondered after this if the snakes she sees might be Adam in his animal form. We see later that he's a shape-shifter when he changes his appearance to look like Lily's mother.
Eventually Adam violently tries to force Lily to surrender her magic powers to him. She and her sister witches fight him off and finally burn him like a witch, to complete the revenge fantasy.
Towards the end Lily finds out she was adopted. Her real mother is one of the witches we saw in "The Craft" named Nancy Downs (played by Fairuza Balk). She was the bad witch with a pet snake who terrorized the new girl with snakes and eventually has her fingers and hair turn into snakes. Apparently she lost the Medusa hair and was sent to an asylum where we see her very briefly at the very end. So maybe the snakes Lily saw were a message sent by her mother.
The snake or snakes we see are California Kingsnakes, a harmless snake and a popular pet.