In chapter “Main slider on header” you can choose main slider type – Carousel slider or Fullwidth slider (1).

Also you can choose what you want to show in the slider (2):

1. Show popular posts
2. Show recent posts
3. Show selected posts or pagesIf you selected “Show popular posts” or “Show recent posts” you can change how many posts will show main slider (it is 5 by default) (1).

If you selected “Show selected post or pages” you should select posts or pages from the drop-down lists (also you can replace the picture with another one) (2).