When you want to create a slide with an image, go up to the toolbar and click on Insert, go to the Images area and click on whatever type of image you want to use.
Now, a box will popup looking for where you are keeping the image, locate it, select in, click the Insert button, the image will appear in the Preview box. If you like what you see, click on the Create button. The image now appears on a slide. When you move your mouse over it, it should be the one with four arrows pointing in different directions. This will allow you to move the image around.
That is basically all there is to it. Good luck.