Log in to admin panel and navigate to “Settings” -> “Language”
Add new language and in ID field set value “pt”, name field can be “Portuguese” written in English or in native language. Also select “Enabled” checkbox and select appropriate flag from existing icons and save.
Language is added, now click on translate button next to Portuguese language
On opened page click on “Auto translate empty fields” button
Then click on “Auto translate empty fields” button. Each term will be automatically translated to Portuguese. Make changes to translation if you feel necessary.
Click “Submit” button at the end of them form.
Repeat translation process until there is no any untranslated term.
Then return to “Settings” -> “Language” page and translate data stored on site like location names, category names, site name and description etc. Links to those are under languages.
If you want to finish translation and then make it visible then disable language , translate all terms and then enable it when it is ready.