Message that kids can be too obsessed with celebrities, and that this obsession isn't healthy.
None, unless you count mob scenes of screaming teenage girls trying to catch a glimpse of their favorite rock 'n' roll singer. Plus, some of the girls literally swoon and faint in his vicinity.
Girls swoon and faint in the presence of a sexy singer. The teenagers are all boy and girl-crazy, but there's nothing more than brief, very chaste kissing in the movie. There is, however, some innuendo (for example, the dad says his daughter will lose "more than sleep" if the rock star stays at their house). There's plenty of discussion about dating, "going steady," "getting pinned," girlfriends/boyfriends, and teenage romance in general. In one conversation, a married couple debates (without ever being explicit about it) whether an engaged couple has had sex or not.
Adults drink at dinner parties.