Cantantes. Which is singers but it’s the most related to your question.
Your secret means your secret
the appropriate defintite article for mochilas is las
las mochilas
1-(sabe-conoce)
2-(se -conozco )
3-(saben-conocen)
4-sabemos -conocen)
5-(se )
The sentence is incorrect because of the words dorms and Queen .
The correct sentence is Es importante que duermas un poco antes de la excursión.
Hope this helps and have a wonderful day!