My intention is translate the Catalan language.
I guess the problem is always to save a whole page - all translated.
Your account is now approved. You should now be able to see, on pages with translations, a link above the language bar. Follow that and you can use a combibox to set your language - Catalan is available as well as Spanish, so choose whichever is best for you. Ask either on Talk/Discussion pages or on #kde-www if you have any questions.