debut; first stage appearance
Refers to one's first performance on stage, or more broadly, one's first public appearance in a new role or field.
彼女は来月、初舞台を踏む。
She will make her stage debut next month.
初舞台の緊張で足が震えた。
My legs were shaking from the nerves of my first stage appearance.
She made her stage debut at the age of five.
The rookie actor gave a splendid performance for his stage debut.