Klavaro uses the "gettext" package to accomplish internationalization. If you are interested in opening the possibility to enjoy it in your own language, you are supposed to work with a team in the Translation Project, translating the interface part (po-file).
To know more about po-files, see the gettext documentation.
In the Translation Project's team for Klavaro you will find the "klavaro.pot" file. Download this file renaming it with the code of your language and using "po" as extension (e.g. klavaro-3.05-pre2.eo.po, "eo" for Esperanto).
There are some programs to help on editing those files:
The advanced modules of Klavaro include some text to practise with. So we must provide a standard text file in your language, a file with the extension ".paragraphs". You don't need to translate it. Just create something new.
I could construct it, even if I know nothing about the language. For that, I could use articles from the Wikipedia. But, if I do it, certainly I'll include paragraphs about vegetarianism, Esperanto, philosophy, etc... :-)
We recommend 30 paragraphs, with an average of 60 words per paragraph. But that depends on your language. Some languages have mostly short words, others have many long ones... Here is the English example, only as a generic reference:
Web site translation is done in a wiki environment of Klavaro's site . Wherein you will find volunteers translating the contents of the site.