shortcuts key photoshop

There isn't a default shortcut for Layer > Rename Layer but you can add one via Edit > Keyboard Shortcuts > Shortcuts for Application Menus > Layer > Rename Layer.

Note that many key combinations are already assigned elsewhere, so you many have to hunt to find a unused combo, or you can simply remap the keys to this shortcut. Once you add it, the shortcut will be listed to the right of the command in the Layers menu.