I hope there'll be a future lesson on contractions. Where and how to use them correctly.
Typo? The option for nu is just the letter "n"
You can say either "Eu nu am timp." or "Eu n-am timp." Two syllables (nu am) become one (n-am). It's a simple contraction that speeds up the pronouncing. Just like "do not" contracts to "don't" for example.