There is no official hotkey to select all layers in Photoshop. You also cannot set one in the Keyboard Shortcuts menu. But it's still possible! Here's a tip on how to select all layers in Photoshop.

Learn how to create a warm, bright and airy filter for your photos. All with just two layers. This Photoshop tutorial will show you how to use the Vibrance adjustment to create a light and airy effect and a solid color layer to give it a warm orange tint.