Translations:Install Desktop Environments/18/en
Optional: Install and use LightDM, the recommended display manager for Xfce
sudo pacman -S lightdm lightdm-gtk-greeter lightdm-gtk-greeter-settings sudo systemctl enable lightdm.service --force
edit /etc/lightdm/lightdm.conf, under [Seat:*] replace the greeter-session setting with greeter-session=lightdm-gtk-greeter