On her first day at Chilton Academy, the soft-spoken Rory Gilmore meets the high-strung Paris Geller, who immediately views Rory as an academic rival. Prior to this encounter, Paris reads Rory's Stars Hollow transcript, courtesy of a student worker in the administration office she paid to sneak her the information out the window. The first day with the younger Gilmore ends up challenging Paris, and a few hours after giving Rory a lecture that she wouldn't make things easy, Rory accidentally broke Paris' castle project after tumbling into her because of a stuck locker. Paris refuses Rory's offered help to put it back together, and in spite the new girl answers lecture questions usually tackled by Paris right away.
Relations between the two remain frosty through their first semester as her crush Tristan gave more attention to Rory than to Paris, whom he considered a platonic friend. After Rory earns a D in a literature class as she tries to catch up with her classmates, Paris jokes bitterly the grade would be perfect to apply for work at McDonald's. Later, the comment would come back to haunt her as an annoyed Rory went off on her for calling her a "loser" during a test she failed to make due to oversleeping.
Paris' backstory is built with each episode after this point. She is forced by her mother to attend Rory's 16th birthday party thrown by her grandparents, and makes it clear she doesn't enjoy it. Later, she bumps into Rory at a college fair, and away from the pressures of school and Tristan, she opens up a little to the girl, discussing Harvard and how she hopes to go there one day because "ten generations of Gellers have gone to Harvard", as does Rory. Though they don't get along, they agree to disagree and be cordial to each other, noting that Harvard is a big campus and they probably would not see each other again after Chilton.
Her hidden crush on Tristan is a major theme for the first season, and as she sells tickets to the school's Winter Formal, tries to bring up the courage to ask him out when he tries to buy his tickets. However she backs off after he makes a flirty comment about her already having a date. She takes out that bitterness on Rory for not wanting him and yells at the girl as she buys her tickets, not realizing that Rory already has a boyfriend in the local new boy, Dean.
Because she needs a date for the Formal, she is forced after asking her mother to take her cousin Jacob as a date. Paris is able to keep it a secret for at least half the dance, until Jacob asks Rory if he could have her phone number and reveals his bloodline connection to Rory's rival. Though Rory doesn't say anything, Paris ends up jumping to conclusions and yells at Rory in front of all at the Formal in attendance, angered that Rory would divulge such secret information. However Rory had said nothing, and Paris unwittingly revealed her own secret.