Select "Files" from the left side menu and then click "+Upload". You are now on the file selection process. Select the desire file to upload and click "Open". The file will start uploading and will appear on the screen after finishing the upload. By hover the mouse cursor over an uploaded file (card) “Details" is appearing. By mouse click on “Details” you may rename the selected file. Also, you can "Open", "Download" and "Delete" the file. Follow the screen below for more instructions.
Click "+New" to continue uploading other files.