NO TROBU LES PAUSES DE CORCHEA , SEMICORCHEA,ETC

Translation: "I can't find the pauses [rests] of eighth notes, sixteenth notes, etc."

1. Select duration for the rest (shortcuts 1-9)
2. Press 0 (zero) to enter the rest

See the Handbook:
Entering notes and rests: https://musescore.org/en/handbook/4/entering-notes-and-rests
Selecting duration: https://musescore.org/en/handbook/4/entering-notes-and-rests#selecting-…
Entering rests: https://musescore.org/en/handbook/4/entering-notes-and-rests#entering-r…