All phrases can be translated in Dashboard > Forums > Phrases admin page, just find the phrase you need, edit and change the value. If you cannot find any phrase, just click the button, add the identical English version as a phrase key and your version as a phrase value.

The "New Member" is a user reputation part. This one should be managed in Dashboard. Forums > Settings > Members Tab. Here you can find all reputation titles and change them.

Please read this FAQ topic for more information: https://wpforo.com/community/faq/how-to-translate/

Thank you for last update, there was awesome!