Aside from asking you should be exploring, probing, reviewing anything you have access to. Clues are everywhere and relying only on others to teach you will be a difficult strategy. If documentation is missing identify and get the docs fixed, opportunities can exist.

I have never interned. Maybe you expect that. I usually get thrown into the deepend of some codebase and asked to figure it out. My advise would be to get use to it and get good at it.