The two lines that imply Anne is nervous about her first day of teaching are:
B "[Anne was] hoping that she did not look as frightened and foolish as she felt."
F "[Anne] sank breathlessly into her chair under cover of the rustle and clatter of desk lids."
In line B, Anne's inner feelings of being frightened and foolish despite her efforts to conceal it suggest her nervousness. Additionally, in line F, Anne's physical reaction of sinking breathlessly into her chair amidst the noise in the classroom indicates her anxious state on her first day of teaching. These two lines together illustrate Anne's nervousness and apprehension about the situation she is in, capturing her emotional turmoil and self-doubt.