Translation:Excuse me, are you staying here until night?
Just a couple of immediate Google finds -- check the titles.. They look legit to me.
That said, I would personally use "until night time" or "until nightfall".
I would disagree with you. E.g. "I will stay here tonight" will generally imply that you are not going to leave until the following morning. "I will stay here until night", however unidiomatic, will convey the meaning that you will actually leave after the nightfall. If you want to be both precise and idiomatic, you can say "I will stay here late tonight" or "I will stay here until late tonight", or something along those lines, but just "tonight" conveys the wrong message.
You can hover over the words with your mouse to get a hint. The words should show in yellow when you see them for the first time. A recording of the sentence is or used to be played automatically, and you can click the speaker button to hear it again. This is how it works in the website version, apologies if you're using an app.
When all else fails: Yandex translate
Oh, it was a listening exercise? I don't recall them ever introducing words in listening exercises, but it's been a long time since I did the tree... I guess you've just got to try to figure out the words from the sounds. Listen several times and don't be afraid to use the snail. I suppose they do still have the snail? That doesn't seem like a great way to introduce words to me.