I don’t know if you have setup already a slider. Go to WordPress admin -> Appearance -> Allslider. Create a new Pictureset (only names without whitespace (” “)), for example “home” or “home_page”.
Then upload some images. After the upload the images are listet in the list at the bottom of the page. Here you can attache the images to a pictureset, for example “home” or “home_page” (one of the picturesets you have created).
Then edit the page you want to show the slider. Below the editor is a box with some settings for this page. Hit the “Slideshow” tab, choose the slider you want to use (for example “cycle”, it’s the default slider we have used in the demo) and the pictureset, for example “home”.
Now publish the page / save the changes and all is done.