You can skip a slide in your presentation by right-clicking on it in the slide navigator and selecting Skip slide.
This will skip your slide in:
You can tell if a slide is hidden if you see an eye with a line over the slide. When the slide is ready, you can select Skip slide again to make a slide visible.
Prefer using the quick menu? Press
Command + K and type in "skip". Press
Return and that will toggle the slide to hide or un-skip.
💡 Keep in mind that this feature limits the visibility of selected slides, but does not remove the content from the underlying data. If the content you're hiding is highly sensitive, you should consider moving it to a separate presentation.