If you don’t have the blog page you need to create it and set as Blog in Settings > Reading. Read here http://8theme.com/demo/docs/xstore/#pages_55_blog_page
You can find all the main moments to set up our theme
In theme documentation. If you need any additional information you can ask here on forum and you will get the response during 24 hours. Or contact us in live chat that you can find at the right bottom of the page.