Did you go to the individual image in the image library? The slider options are located in the editing area of each image. Go to the image, click edit. Scroll down to Slider Options. Slide the button over to “yes” and a list of other options will appear.
If you have not yet created a slider, you can do that at the bottom. MAKE SURE TO UPDATE YOUR IMAGE after you have made all of your selections, otherwise this will all be lost.
Then in the customize it! area, you have to go into the “Front Page” area and select the slider you created. If you only add a single image to the slider, that’s all that will show up. You have to keep adding images (in their own editing area) to that same slide and then it will begin scrolling through whatever images you individually add.