With the opening sequence, the trailer for The Punisher pretty much lays out everything that you need to know about Frank Castle, even if you have not seen Daredevil Season 2.
Although it seems to create a bit of continuity gap (it’s probably just a dream sequence), The Punisher trailer opens with shots of Frank Castle spending quality time with his family before a masked soldier enters his bedroom and abruptly shoots his wife point-blank in the face.
He’s a trained killer who decides to commit himself to a never-ending war on crime following the murder of his family; it covers the basics so even newcomers can get on-board easily.