Super key – Brings Activity
    Alt + F2 – For quickly running commands
    Alt + Tab or Super + Tab – Switch between the running applications
    Super + A – Show the list of applications.
    Super + Page Up or Down – Switch between workspaces
    Ctrl+Alt+Delete – Power Off
    Super + L – Lock the screen
    Super +M – Bring down the notification tray
    Ctrl+Super+D – Minimize all the windows and show desktop

https://help.gnome.org/users/gnome-help/stable/shell-keyboard-shortcuts.html.en