Season 1: I Don't Give a Damn 'Bout My Bad Reputation
In the beginning: In a train station, returning from boarding school for junior year after being MIA. Although Serena doesn’t actually have any friends, she doesn't know it yet
Hook-ups: Dan. Later, she tells D she slept with someone else but she really didn’t
Feuds: Blair (Leighton Meester) (we don’t know why some people can’t just get along...), Georgina (she crazy — and she’s intent on being BFF with Serena OR ELSE).
Scandals: Blair finds out S & N lost their virginity together (and that's why S ran off to boarding school... sort of). Serena's little brother Eric is in a mental hospital (attempted suicide) and is gay. There’s lots of fighting with Lily about that... Oh yeah, and S thinks she murdered someone and Georgina tries to blackmail her so she’ll hang out with her again. Yeah, really.
Relationship with Blair: Not friends until 3rd episode, then jealousy from B about her mom's love for Serena. But B comes through when she needs it.
Relationship with Dan: Awkward at first with many missteps as Dan discovers S isn't who he thought she was. Then okay, then love. Then they break up after she lies to him to protect him from what she's done.
Biggest Moment: Comes clean to Lily about the Pete cocaine incident and is absolved of guilt.
And in the end?: Dan has broken up with Serena (as he’s wont to do) she runs off to the Hamptons.