I am certain that in an episode Caroline implied that Elena used to be a party girl before her parents died.. i really am certain she sagte it, can anyone help me.. Did she say it? and if so what episode/season?

I don't know if that's exactly what Du mean, but there's a scene in which Caroline says about Elena: "She used to be way Mehr fun!" It's in episode 3 of the first season. Du can see the scene below!

Episode 2 and season 1

In episode 1x20 Elena told Stefan that the night her parents died, she went to a party that her parents had told her she could not go. Then they had to go get her and on the way Home from the party they crashed.
She liked going to parties and stuff, so yeah, I guess Du could say she was a party girl.

She told Damon too in season 1 episode 11 :"I used to be Mehr fun "