How do I find which learners have completed which courses?

Hi!

I am brand new to LMS administration, and we are prepping to launch our LMS in less than two weeks. As an incentive for our employees to try it out, we want to hold a raffle. Any employee who completes at least one mandatory course will earn an entry in the raffle.

My problem - I don't know which report will tell me who has completed each mandatory course, and when? Can you please point me at the right one, and what filters I need to use? Thanks!

Jeff