The amount of free storage space depends on the service plan that your company uses. Information about your plan can be found in the Administration > Licenses.
Users included in the Administrators group can check how much free space is left. To do this, go to the Files section and click on the link in the lower left corner of the page.
In the pop-up window, you will see how much drive space is occupied by your company's files. To free up space, you can empty the contents of employees' recycle bins.