This prayer is often recited before blessings, especially when a bishop gives the blessing at the conclusion of mass. It is from Psalm 124:
Our help is in the name of the Lord / who made heaven and earth.
Adiutorium nostrum in nomine Domini / qui fecit caelum et terram.
Here is a free Memrise course to memorize the meaning of these words. Work hard. Keep trying. Practice for a week or two and you will know this all by heart.