YA Mystery about a girl whose best friend goes missing. Read late 2000s.

[Emily]

Trying to find this book or trilogy I can’t remember that I read in high school in the late 2000s. Girls best friend goes missing, girl tries to solve the mystery and find her friend, teams up with boy. There is a room or club or bar that the girls went to that is related to mystery and I think in the title of the book.

[Becca]

The Party Room series by Morgan Burke? The first book is Get It Started.