Your choice would be "у нас нет времени для ожидания". You can say so, but it is a very rare choice to express this thought in Russian (for example you can find this one in verse). It is better to say "у нас нет времени ждать" or "у нас нет времени, чтобы ждать" (they are equal)
Exactly. Вре́мя is nominative, вре́мени is Genitive. You can see the declension here: https://en.wiktionary.org/wiki/%D0%B2%D1%80%D0%B5%D0%BC%D1%8F
There are 10 words that are declined like this: вре́мя 'time', и́мя 'name', пла́мя 'flame', бре́мя 'burden', се́мя 'seed', зна́мя 'banner', пле́мя 'tribe', те́мя 'top of the head', стре́мя 'stirrup', вы́мя 'udder'.
We have no card with 'no' here :D Only 'not' card ><
So I'm a tad confused and I apologize if it's stupidity causing it. Later, in the lesson "Nothing", we learn "Нам некогда учиться"-"We don't have time to study" and I think I was told that one doesn't use "у нас" for that sort of situation. But here, it's what's correct? If someone and/or a native could help explain this to me I would be incredibly grateful.