You create an organization report directly from your organization settings. if you are unsure of where you find your organization settings, there is another article in this FAQ regarding organization settings.
All the way at the bottom of your settings, you will see a "Download organization report" button.
Clicking this button will start the process of creating a report for all projects in your organization. Depending on the amount of projects, this will take some time.
After it has finished creating the report, you will be given a report in the form of a .xlsx file.