From the File menu, choose New, or click on the New Presentation button from the Standard toolbar.

Select “Blank Presentation” from the New presentation task pane

From this window, you can also choose to create your presentation with a design template or have PowerPoint help you create the presentation with the AutoContent wizard.

PowerPoint will automatically create a title slide.

To insert additional slides, from the Insert menu, choose New Slide.

In the Slide Layout pane, select a layout for your slide.  Use the Title Slide layout for title slides and a Bullet Point layout for slides with bullet points.  There are also layouts for slides with graphs, pictures, tables, and many combinations of these layouts.