I can open & run the software but I can't seem to play with any puzzles? I see the donuts on a list but clicking with my mouse/hitting every key I can think of does nothing.
I was stumped for a moment, too. You can't access puzzles from the Puzzle Collection screen. Instead, look to the bookshelf. The top-left rectangle, with a little shape on it, is the first puzzle. Completing it unlocks the next.
