LadoPC You have to set the layout that matches your keyboard and use it normally. Basically set the same layout as in the GUI so you use the same key combination to type ñ everywhere.
I don't know what your keyboard layout is and I don't know what your configured.
Normally this shouldn't be a problem because if you connect to the GUI then you open a terminal, it will use the configured keyboard layout so 99% of the users won't have any issue.
BUT if you switch to a TTY console or you have LUKS encrypted volumes that requires a passphrase to decrypt your hard disk and you don't use a US keyboard layout then (and only then) you will run into problems. The command I gave allow you to set the keyboard layout for the console.