Oh  .. xfce works like popular tiling windows manager - i3 or sway  .. you can map your keys in the settings but out of the box super + left arrow  is to align the window on left half of the screen .. and super+ right arrow for alinging on the right side  .. 

you can check your jeyboard maps in Settings > windows manager > keyboard   ... and edit the shortcuts there  ..  Its kinda same in gnome and cinnamon too  .. bit here and there