It is recommended that when planning to create a new report, you should first be logged in as the reportdesigner user account. 

Note: Only the account that populates the report is able to edit the report and the reportdesigner user account will have many template reports already populated, allowing you to use one of those reports as a starting point. It is recommended that when you plan to create a new report, first log in as the reportdesigner user.

You can open an existing report by entering the Report Designer and clicking on the folder icon in the top left corner, in the dropdown click on 'From Server' and in the window that pops up click the folders Student- Custom Reports. 

If the reportdesigner user has populated the default template reports then you can expect to see them here:

All of the default reports are properly connected to the data source and have parameters and queries already defined. 

The setup is already complete, making less work for you. 

Once you open an existing report you should save it under a new name in order to differentiate your custom report. Click on the save icon in the top left and in the dropdowns click on Save As- To Server, save the report under the Student- Custom Reports folder along with the rest of the reports:

You now have your custom report saved and are ready to start design