How to create a new query report

I need to identify all users in my PMP database, who has not been shared any resource or account access. i.e. inactive users. I went to Canned reports and custom reports and nothing gave me the impression that, any of the existing reports have been created for this purpose.

Then I went to the query report tab, expecting to pick and select which fields I want to search for which values, but instead I faced a blank SQL query field. First of I do not have any DBA experience to cobble together a sql query, but even if I did, I have no idea about what table names and field names are. Is there document where this information is disclosed ? I mean I can get a local dba help me put together a simple query but "how" is the question.

Or is there any other way to modify the existing reports to do what I want to do ?