I see two problems in your question.
First of all, you do not have any results on your search. In order to tackle this, you will need to solve your second problem, which is being able to see the document's properties.
To see documents properties, you will need to give yourself "Index Browser - Full Access" Permissions. You can do this in the the Coveo Administration Tools (CES7) by default on [coveoserver]:8081. Simply navigate to Configuration >> Security >> Roles. Then select your user and give the Full Access permission.
For more information, please read: https://onlinehelp.coveo.com/en/ces/7.0/administrator/about_administration_roles.htm
Also, a quick search on search.coveo.com would have told you everything: https://search.coveo.com/#q=you%20do%20not%20have%20permission&sort=relevancy
Now that this is solved, you will be able to see the permissions tab in the detail section of your document in the Index Browser, with this, you will be able to know who has access to your document.
On the query side, use the CES Console to view the permissions on the user at query time, then compare with the information you have on the document in the index browser.
Now a common issue is when no permissions are applied on the documents, this is a normal behavior of Coveo when it encounters a failure while refreshing the securities. It will simply deny everyone to avoid a security leak.
What kind of failure you will ask?
Well a security cache refresh failure is a common one. The cache refreshes by default every day at midnight server time. You can manually refresh it to test : https://onlinehelp.coveo.com/en/ces/7.0/administrator/refreshing_security_caches.htm
Keep the good old CES Console open during the refresh an you will see the errors in bright red. From there you should be able to see the cause of your issue.