You can add a slidershow on a page of your website, if you want to add several photos in a single block, this article explains how to do it.
In order to modify your slider on your website, simply go to > Website > website > Customize:
You will then arrive at the homepage of your website. If it is not a change on the homepage you're trying to make, go to > Pages to find the page where you want to modify your slider.
On your left menu, scroll down to add a new block by clicking on > Add an element to add "Slider" or select the block "Slider" already created:
Now go to > Content and > Image to change/add your first slide or > Add slide to add new photos from your library:
The photo will download and appear at the end of the photo library. Click on the photo to see it appear and then save.
Do not forget to click on > Save to save the changes.