Bonjour Chandni,

I am sorry I didn't look at the video. 

When you want to ask to someone about what is going on, you ask "Qu'est-ce qu'il y a?" = What's up? What's wrong? (literally translated as "what is it that there is?"). You would answer this question, if you want to be very polite, by saying "Il y a que je suis content" = simply translated in British English as "I am happy" (literally translated as "there is that I am happy").

In the expression "il n'y a que toi", que is part of an expression of restriction "ne ... que". It can be translated to only/just/nothing else. 

Il y a que je suis content = there is that I am happy

Il n'y a que toi = there is only you

Il n'y a pas que toi = there is not just you

See following link for "ne...que":  how-to-use-restrictive-ne-que-with-simple-tenses-to-express-only-negative-expressions

I hope this is helpful.

Bonne journée.

Bonjour Chandni,

I looked at the lesson you are referring to and I can't see an expression with "que" anywhere in the content. Could you give more details please? 

Merci bien.