Follow this steps you learn: how to configure Joomla Translate (SEF Translate) - Joomla plugin for automatically Joomla website translation, free version. If you have Pro or Pro Commercial version, please read this tutorial How to configure Joomla Translate Pro version
3.1. Set Translation Method for you website:
In free version of Joomla translate you may select only Instant then your website will be translated without redirect when the user clicks on language flag or chooses language from the drop-down list.
3.2. Enter languages which you want to display in drop-down List on frontend. If you choose no language, drop-down list won't be shown on frontend.
3.3. Enter languages which you want to display in the form of Flags on frontend.