This File contains information about how exactly you can get a gui for arch linux
Open the Arch Linux Terminal & execute the following command. Be sure to only press enter when it asks you something. This ensures, that the default setting is choosed.
sudo pacman -Syu
Next we'll have to Install the Xorg Package before moving to the GNOME Installation. So do the following:
sudo pacman -S xorg
Now it's time to Install GNOME on Arch Linux. Proceed like this:
sudo pacman -S gnome
After that, the GNOME Desktop environment is installed. Now we have to Enable it.
sudo systemctl enable gdm.service
Be sure to start the GNOME Service after enabling.
sudo systemctl start gdm.service
reboot and you're good to go.