Right. So I know the first answer. Passe compose is something that happened in the past, for a short period of time. Imparfait is something that happened also in the past, but for a long time.
e.g J'ai mangé un hamburger (passe compose)
I ate a hamburger
OR
Quand j'avais 10 ans, Je mangais un hamburger
When I was 10 years old, I ate hamburgers.
Hope this helped! :)
