If you don't speak the language of the website you're using, try viewing the site in the Google Chrome browser. Just right-click on the page and select "Translate to English" from the drop-down menu. If you need a rough translation of a document such as statute or court judgment, copy and paste the text into Google Translate.
If no comprehensive database is available for your jurisdiction, use secondary sources such as books, journal articles, reports, or the Foreign Law Guide to identify a citation (such as the decreto number) for the law you need. Then search for the law online by Googling the citation.