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.

Naomi finds herself in trouble when she fails an assignment, and Ryan and Kelly bring the issue to Harry's attention, while Harry struggles with a disturbing revelation about the result of a secret tryst with Naomi's mother, Tracy, from many years ago. Meanwhile, Dixon learns more about Navid when they team up to try to pull a school prank against Palisades High. Annie meets a potential love interest in the form of drama student Ty Collins, who turns out to be the wealthiest student at West Beverly, and who spirits her away for San Francisco for the evening. Silver posts the story about Ethan's infidelity with Naomi on her Internet blog, while Adrianna continues her self-destructive slide into drugs and debauchery. Also, Ryan tries to ask Kelly out on a date, but she has to find a babysitter first for her four-year-old son, and former West Beverly alumni Brenda Walsh, now a successful Broadway and London theater director, arrives back in town to help put on a new school play.

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.

After spending several days in the hospital recovering from a near-fatal drug overdose, Adrianna tries to make amends with Naomi. But Naomi refuses to forgive Adrianna for her betrayal. While serving her detention, Naomi meets a trouble-making punk, named Ozzie, who could spell trouble for her. Later, Adrianna makes a connection with Navid, who helps her through her situation as she's accepted into a rehab clinic. Meanwhile, Annie and Ethan finally take their rapidly growing romance to a new level during the school's annual homecoming dance, causing Naomi to feel jealous. Dixon asks Silver to the dance, but she turns him down for she feels, in her liberal and radical mind, that Homcomming is the scene of the morally corrupt. Ryan believes that the new student, Kimberly, is a narc after he sees her purchasing drugs. Also, Debbie confronts Tracy about the time Tracy kissed Harry.

Annie overhears Sean in a suspicious conversation with someone over the phone, which raises her uncertainty about whether Sean really is who he claims to be. Meanwhile, Brenda tries to make amends meet to Kelly after confessing about a tryst she had with the departed Ryan Matthews. But Kelly and Brenda have to team up to accompany Adrianna to a group therapy session for recovering addicts where after she learns that a friend of hers is HIV-positive, Adrianna goes to a clinic to get tested, but receives some other potentially life-changing news. Elsewhere, Christina invites Dixon over at her house for a Gospel gathering where she makes a startling revelation to him which could shake his romance with Silver.