To get an overview of your landing pages, you can click on the Landing Pages button located on the left side menu.
On your Landing Page's overview you can find information for each landing page you have created. The sixth column of this table indicates the status of each landing page. There are a few different statuses that you might come across:
The above terms are mostly self explanatory - for example the Published status obviously designates a landing page which has been published. But just in case they're not as self explanatory as we'd like to imagine, clicking on the above links will give you as much information as you might need for each status, including some details which you might deem useful.