Fig.: to muster up all one's courage to perform a difficult or dangerous action

At last I gathered up my courage and asked out the prettiest girl in school

Finalmente ho preso il coraggio a due mani e ho chiesto un appuntamento alla ragazza più bella della scuola

The girl took her courage in both hands and confessed to her parents that she was pregnant

La ragazza prese il coraggio a due mani e confessò ai suoi genitori di essere incinta

This English expression is probably a calque of the French phrase "Prendre son courage à deux mains"