There ARE differences between Catholic and Protestant translations, as there are differences between any two translations. Different translations allow for different interpretations!
The "Lutherbibel" is the standard translation used by the "evangelische" or protestant church in Germany.
The "Einheitsübersetzung" is the standard work used by the Roman Catholic Church in Germany.
PS I teach English and German, so if you'd like to learn either, please get in touch!