I am looking to find top 10 posts which has gain traffic, lost traffic etc.
If by top 10 posts you refer to most visited pages, once you have opened the view for your website under the Reporting tab:
- Set the date range (in the upper right corner) to Last 30 days
- Go to Behavior > Site Content > All pages to get a breakdown of the most popular pages by default metrics.
- To filter out only blog posts, go to the search bar (just bellow the graph on the right side) and type /blog or /blog-post or the part of the URL category that your site uses for blog posts.
Hope this helps.