This was a teen horror book from the 90s. It is not Point Horror, Fear Street, or Goosebumps. I am sure the the title was "Bad Blood"; however, I have searched online and can't find it.
The story of what I recall was a guy named "Mike", I think, and he is in high school and is in love with this girl. He wins tickets to a gig for their favourite band (I think they were called "The Zombies") so he asks the girl to go and she agrees.
On the drive to the gig they approach a bridge above them and someone throws a brick at the car and runs away. The date is ruined and Mike (if that is his name) I think persuades her to carry on with the date. They get to the gig only to discover I think that the tickets are fake. The girl after the the events demands to be taken home.
Throughout the book bad things happen to both of them: I think a pet is killed and other friends die, etc. Turns out it is Mike's best friend who is stalking them, as he is jealous.