Final answer:
The first event held in 1989 with just five categories for awards was the Nickelodeon Kids' Choice Awards, distinguished by audience-voted winners and the iconic slime.
Step-by-step explanation:
The event that was held for the first time in 1989 with only five categories for awards is the Nickelodeon Kids' Choice Awards. These awards showcase a wide range of talent in the entertainment industry and are well-known for the iconic green slime that often covers the celebrities involved. Unlike more traditional awards shows, the winners are chosen by the viewers, mainly children and teens, who vote for their favorite movies, television shows, and performers. The initial show had just a handful of categories but has since expanded to include a diverse range of categories across various entertainment genres.