The Wilson family arrives in Beverly Hills, after Harrison "Harry" Wilson takes a job as the principal at West Beverly High School, while his children, Annie and Dixon, attend the school during their first week much to the awkward circumstances of their father watching over them, while Harry and his photographer wife, Debbie, also keep a close eye on Harry's washed-up, alcoholic, actress mother, Tabitha. For Annie and Dixon, the school is one big culture shock for Annie, a sweet and friendly girl with a passion for the theater, and Dixon, a star athlete and scholar who was adopted by the Wilson family after they took him in as a foster child. Annie and Dixon have a close sibling relationship, which they'll need to help them cope with all the new cliques and classmates, including Naomi Clark, a hot and stereotypical spoiled rich girl who believes that money buys everything; Ethan Ward, Annie's former boyfriend from Kansas who's now Naomi's boyfriend, and a popular lacrosse star whose abilities rival Dixon's; Navid Shirazi, an aspiring student reporter who heads up the school's daily TV newscast; and Erin Silver, a rebel and wanna-be socialite who produces and stars in a YouTube-type video series, and who develops a crush on Dixon. Adrianna is a fellow student and theater "goddess" who is Naomi Clark's best friend... and Ethan Ward's secret girlfriend, and who has a serious drug addiction; George Evans is an arrogant West Beverly High student, who takes an instant dislike to Dixon because of his race (Dixon is black). Wendy is "sexy vixen" student at West Beverly Hills High who takes every advantage of her looks; Ty Collins is another student and theater major. Even the faculty seems hip and sophisticated at the school whom include the smart and funny teacher Ryan Matthews, beautiful guidance counselor Kelly Taylor, and successful theater actress-turned-high school-musical director Brenda Walsh. The Wilson family has just begun to realize how much their lives are about to change.

Dixon and Annie find their Friday night plans disrupted after Debbie and Harry plan a family bowling night without consulting them. So, Annie plans to sneak out of the place to meet with Ty to attend a rock concert, while Dixon plans with Navid and Ethan to sneak him out so they can watch a movie at Navid's house. Meanwhile, Naomi has an unpleasant evening with her estranged and selfish businessman father, Charles, who puts her off for work. Also, Dixon invites Silver over to the Lucky Strike Bowling Alley, and he later finds Silver asleep in his car. Silver then confides in Dixon about her troubled home life and how her drunkard mother, Jackie, verbally and physically abuses her. The news gets back to Kelly who confronts Jackie about it, while at the same time, Kelly continues to be sought after by Ryan who tries asking her out on a date.

Annie and her parents, Harry and Debbie, are surprised to learn that West Beverly's theater director can no longer oversee the school musical. Tabitha offers to direct the musical play, but her eccentric and demanding attitude does not sit well with Annie or the other actresses. Kelly persuades Brenda to take over as the play's director, much to Tabitha's chagrin. But Kelly and Brenda end up continuing to argue over Kelly's continuing involvement with Ryan and taking up time with Kelly's son, Sammy. Meanwhile, Dixon tries to get a part time job at the Peach Pit coffee shop to get money to pay off a bully after Dixon accidentally dents the bully's car. Naomi becomes more distraught over her parents, Tracy and Charlie's, open-marriage arrangement, and she eventually confronts her father's mistress to show her true anger towards her. Elsewhere, Annie's growing relationship with Ty is the talk of the school, which leads to Ethan, who's growing more uncomfortable and jealous, to try to get her attention.

As opening night for the school play nears, Harry catches Annie kissing Ty, which makes him worry that she and Ty are moving too fast with their growing romance. Silver, stressed out from her job as the stage manager, gets some comfort from Dixon. Meanwhile, Naomi tries make her mother and father get back together, but Tracy's mind to divorce Charlie is made up. On the opening night of the play, the star Adrianna's drug use comes to surface from being under constant pressure from her overbearing mother, Constance, and when Brenda discovers this, she replaces Adrianna with Annie in the lead alongside Ty. But when both Brenda and Kelly confide in Constance about her daughter's drug abuse, Constance (a secret drug abuser-in-denial herself) refuses to believe them. Afterwards, Adrianna successfully gets her revenge when she manipulates and breaks up Ty and Annie's romantic get-together at a celebration party at a local hotel.

Adrianna and her evil-witch-mother, Constance, plot a cruel revenge against Annie and the rest of the faculty at West Beverly whom they think cheated Adrianna out of her role in the school play. Debbie's boss, Antonio, offers her a job to shoot a fashion show for Nylon Magazine during Fashion Week, where Annie uses the opportunity to her advantage for a class assignment, while her father advices her to try to make amends meet with Adrianna in order to try to catch her in the act with her substance abuse. Naomi believes the upcoming fashion show could help her parents' marital problems and she plans with Ethan to try to break up her father and mistress and have her mother, Tracy, meet with Charles, but it only makes matters worse. Ty and Annie's relationship is put to the test because of Adrianna's meddling. But when Adrianna lets her guard down and reveals to Annie that she lied about hooking up with Ty to break them up, it results in Annie declaring war. Silver is pursued by Debbie's sleazy client, Tony, to work in modeling, while a jealous Dixon becomes aware about what's going on, while Navid feels like he's the 'third wheel' to Dixon and Silver's growing romance. Meanwhile, Kelly receives a phone call from Sammy's father that could change her relationship with Ryan when she's offered to move to Wyoming to join Dylan, while Brenda, with her work at West Beverly finished, plans to return to New York.

As Silver's "half birthday" approaches, she decides to spend a spooky evening by watching horror movies with her friends at the famous Hollywood Forever Cemetery. But Dixon is not eager to attend when he reveals to her that he does not watch horror films. Meanwhile, Harry's past returns to haunt him when Tracy reveals she is searching for their long-lost illegitimate son. Annie and Ethan are paired up for an assignment, which leads to a possible romantic connection after the two take care of a baby. A mysterious new student, named Kimberly MacIntyre, arrives at West Beverly which considers with a police raid on the school searching for narcotics which leads Naomi to cover for Adrianna when Naomi takes the fall by taking her cocaine stash. After Naomi confronts Adrianna over her escalating drug addiction, she agrees to come forward to clear Naomi, but Adrianna soon goes back on her word when she lands another acting role which could jump-start her acting career and make her difficult-to-please mother proud. Also, Ryan seeks to explore his horizons since his breakup with Kelly by dating an attractive, but dim-witted actress.

Ryan Matthews returns to his job at West Beverly High which causes a mixed reaction for both Kelly, as well as Silver who finds herself writing a class paper on the book 'Heart of Darkness' to win back his trust after he rejects her from his class. Meanwhile, Annie decides to audition for the school's drama production of 'Antony and Cleopatra' and sets her sights on the lead, while she asks Ethan to audition for a role in the play so they can be closer together, while Annie also has a run-in with her one-time boyfriend Ty Collins. Adrianna becomes more uncertain about her pregnancy and refuses to deal with the problem. When her mother goes missing, Naomi is asked by her father, Charles, to move in with him and his mistress at their Malibu beach house which makes the situation very awkward and uncomfortable for everyone. Elsewhere, Silver and Dixon continue to experience bumps in their relationship which leads him to decide if he wants to end his romance with her.

Donna finds herself in a dilemma when she confides in Kelly during a night on the town that she must decide between returning to Japan and being with David, or moving back to Beverly Hills and keeping their 20-month-old daughter, Ruby, which leads her to decide to open up her own design shop in Los Angeles. Meanwhile, Silver is the topic of gossip at West Beverly due to her recent mental issues and does not know if she is ready to return to school. While Annie and Naomi try to patch things up between them in order to help Silver, Annie soon overhears that Naomi's father is being served a sexual harassment lawsuit, and she keeps it to herself... and later regrets it when Naomi is evicted from her hotel suite. Ethan continues on his downward spiral due to Liam's bad influence in wanting to be a bad guy as Liam is. Also, Adrianna and Navid meet with potential adoptive parents for the baby. Elsewhere, Harry and Debbie hold a yard sale when they finally sell their Kansas house and try to get rid of all of their old house's possessions as they plan to move out of Tabitha's house and to find a house of their own in Beverly Hills.

Following their engagement, Navid and Adrianna celebrate their respective bachelor and bachelorette parties. While Adrianna feasts with Annie, Naomi, Silver, and their female friends at the Wilson home, Liam takes Navid, Ethan, and Dixon to have a wild night on the town with some college girls at a burlesque club. Meanwhile, sparks fly between Ryan and Jen, and Dixon continues to feel unappreciated by Silver. Jen also persuades Naomi to stand up to their father as well as move in with her at a local house, while Naomi continues to grow more insecure as well as jealous over Liam when she sees him talking with Annie whom he sees as naive and holding back her own dark side.