The best way to manage files is to upload them in different folders:
Click “New” button and enter the name for the Folder
...
Additional actions
...
Click on more options icon near selected folder:
“Add folder” - add subfolder
“Rename” – rename selected folder/subfolder
“Remove” – remove selected folder/subfolder
...
Remove files
To remove files select them and click “Remove” button
Sort files
To sort files click “Sort by” and choose your criteria
More options
Click on more options icon to make additional actions:
“Download” – download selected file
“Remove” – remove selected file