Since the server paths differ from customer to customer, they can only be queried while you are logged in into the easyname control panel. Click on [Web Hosting] → [Data Sheet] to see all server paths such as the absolute path.
In your server path, you then have the option to navigate to the following folders
db_dumps - In this folder, the snapshots of your databases are created and then transferred to the backup server. No files should be transferred to this folder.
files - Here you can store required files that can not be accessed via a link defined in the subdomain settings.
html - In this folder, all the files must be stored, which are then accessed via your domain.
log - Log files are stored in this folder. E.g., error.log, php_error.log, php_slow.log, etc.
tmp - Temporary files can be loaded into this folder.
Please note, that there is no "root" access as in the traditional sense, as easyname is a shared web hoster.