MacOS Finder FAQ: How do I open a new Mac Finder window using the keyboard?
Keystroke to open a new Finder window
To open a new Mac Finder window using the keyboard, make sure a Finder window is currently the foreground application, then press the [Command][n] keystoke.
This will open a new Mac Finder window, and is equivalent to clicking the File menu, and then clicking the New Finder Window menu item. (It's also much faster.)
If you like to use the keyboard a lot, here is a list of more Mac Finder keyboard shortcuts (keystrokes).