We suggest Poedit, to translate Avventura theme. It’s available for free on poedit.net.
Open Poedit, go to File > New from POT file and choose avventura.pot , under avventura/languages/ and choose your native language.
When you’ve finished, upload bot files with your language code (for example it_IT.po and it_IT.mo ), under the language folder of Avventura using a FTP client.