You can add gnome desktop environment by installing
gnome package as a whole. But this is not the recommended way of installing gnome following the KISS mentality in Arch Linux. Let’s install only the basic packages we need in order to have a working desktop environment and install additional packages in the future as needed.
Install the basic packages:
# pacman -S gdm gnome-shell nautilus gnome-terminal gnome-tweak-tool gnome-control-center xdg-user-dirs networkmanager gnome-keyring network-manager-applet
Enable gdm service:
# systemctl enable gdm # systemctl enable NetworkManager
Login as a normal user (not root) and then create default home folders: