This article provides a detailed introduction on how to delete slides in PowerPoint.
For instance, suppose a presentation file contains 3 Slides:

If you wish to remove the first slide, follow these steps:
- Right-click on the slide you wish to delete -> Delete Slide:

- The Slide is successfully removed from the list:

- In addition to that, to delete one slide, follow these steps: Click on the Slide you want to delete -> press the Delete key on the keyboard:

Here is a detailed guide on how to delete Slides in PowerPoint.
Wishing you all success!