TYPO3 v8 has reached its end-of-life March 31st, 2020 and is not maintained by the community anymore. Looking for a stable version? Use the version switch on the top left.
You can order Extended Long Term Support (ELTS) here: TYPO3 ELTS.
If you need more information on how to translate a web site, you should read the Localization Guide. It contains information on how to set up a multi-language site and how to actually do the translation and localization.
If your activities are not limited to editorial work, you may want to further learn about TYPO3 CMS by following the TypoScript in 45 minutes Tutorial which is a preparation for the Templating Tutorial.