It's actually pretty rare for any video game to ship with a manual nowadays, most games instead include a short tutorial during the opening portions of the game or include a map of the control scheme in their Options area either of which walks you through the basic controls.
For Garden Warfare 2, if you enter the Options Menu of the game you should be able to view the default settings for the PC/Xbox/PS4 controls as well as being able to customize them to your liking. If you happen to be using an Xbox controller there is also a listing of the default settings here https://help.ea.com/en-us/help/plants-vs-zombies/plants-vs-zombies-garden-warfare/basic-controls-for-pvz-garden-warfare/
