Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is a quirky Wes Anderson film with a complex story about a documentary about a play called Asteroid City. The cast and art direction are excellent and it has the fun quirky music soundtrack we expect in a Wes Anderson film. It begins with a trivial snake scene in the background. We don't see the snake, we only hear little girls talking about it.
Some time in the mid 1950s three little girls are traveling with their father and brother and the ashes of their recently-deceased mother in a Tupperware container. They're going to Asteroid City where their brother is participating in a junior stargazer convention and where the motel has sells cocktails and real estate in vending machines. We first see the family in a station wagon pulled by a tow truck as it brings them to a service station in Asteroid City. The girls get out of the car and immediately walk over to the road to investigate a dead snake and poke it in the head with a stick. That's everything there is about snakes in the movie.
The girls are all named after women in classical mythology: Andromeda, Cassiopeia, and Pandora. They tell a counter clerk that they are a mummy, a fairy, and a vampire. When their grandfather calls them witches in training, they correct him, saying they are real witches - part witch and part alien. I would call them herpetologists in training.