You can delete items such as documents, files, or activities from your course using the Batch Editing option. Other items like calendar entries or announcements cannot be deleted this way.

To delete in batches, click on ... at the top of the course body and select Batch Editing.

In the panel that opens, you will see all the course content items with checkboxes to select them. Check the ones you want to delete and click Delete Items at the bottom.