The thing with 'Hola,' though, is like saying 'hi.' It can be used at any time of the day. However, for this assignment, you might want to consider using it for the scenarios at night. 'Buenas noches' is more like 'good night' as in 'its time to go/sleep.'
Also, I noticed a mistake you made. 'Buen<u>a</u>s' is for 'tardes' and 'noches.' Buen<u>o</u>s is for 'días.'
Another mistake you made is that you put and 'i' for días. It has to be í, not i.
