Using shortcut keys on Photoshop can save you a tremendous amount of time. The only problem for a photoshop beginner is getting used to where they are and the different combination of pressed keys at the same time. To help you get used to the shortcuts in Photoshop there is a free tool that will give you a visual representation of the keys.
Download it from here: waldobronchart.github.io/ShortcutMapper
It is called Shortcut mapper, rather appropriately and was made a bloke called Waldo Bronchart. Thanks Waldo! The application can show the short cut keys in windows and for Mac and it is really fun to use which is another reason as to why it will help you along the way to learning photoshop shortcut keys!