Hi there,
The posts slider requires little setup at all. All you need to do is edit the page where you wish to display it, and scroll down to the page meta options (below the content editor). You will find the option to enable the posts slider here. Once you’ve enabled it and saved the page, you will see it visible.
The way to posts slider works is that if a featured image (or slider image) is set for the post, then it will show here with the slide up overlay. If not, it will show the holding slide with the text. You can set the featured image or slide image for each of the posts when you edit them.
Hope that helps.
– Ed