To upload the files that make up the site, this can be done via SSH (via the terminal) or via SFTP (via filezilla, fetch, ...). The directory that is read to display the site is :
/home/users/name/Sites
You have to put your files there, and in particular your index.html or index.php, etc.
From a terminal run the command:
ssh name@www.ceremade.dauphine.fr
To connect via sftp, you can use a dedicated software like FileZilla.

In the field Host put www.ceremade.dauphine.fr, then your Identifier and your password then 22 in the field port then click on quick connection.