The ShooterGame would be a good recommendation, but I don’t believe it’s up to date.
I would start with your actual project, instead of learning just to learn that’s asking for a headache. Start with a blueprints project, you can always add C++ to the project later. Start with putting afeature into the kit that interests you most, like the a sidescroller. There are tons of resources, you don’t need a book. Here is a tutorial I grabbed randomly for sidescroller, it looks well put together, I have not followed it, but give it or something like it a shot. http://3dmotive.com/series/build-a-side-scroller-in-ue4.html