The Naruto manga itself doesn't have fillers. Fillers are a common thing in anime to extend the runtime or bridge gaps in the manga's story. But the manga sticks strictly to the main plot.
In general, mangas don't typically have fillers. They tend to have a more focused narrative without unnecessary additions to stretch the plot. But there can be exceptions depending on the author's style and the publishing requirements.
Yes, manga can have fillers. Sometimes authors use them to flesh out characters or settings, or to give themselves more time to plan the main plot. But too many fillers can make the story drag.