>Permission non accordée
The user account doesn't have write permission under /etc where global (=for
all users) settings are stored. So perhaps try running the -d with sudo.
>How do I update a free software ?
The update manager takes care of it. However, the version in the repositories
might not be the very latest version. This might or might not be a problem
depending on the software. If the newest version from the web page doesn't
require newer libraries than what is available on your system, you could
compile it. There might be binaries available too but use those at your own
risk.
>how do I create a torrent file
To do so with transmission apparently requires the package transmission-cli
and using the command transmission-create. After you've installed the
package, read the manual page man transmission-create
