which kernel do you have installed?
pls output from:
inxi -Fxxxza --no-host
or
uname -a
the driver install should work like this:
sudo pacman -Syyu
sudo pacman -S dkms linuxXX-headers
pamac build rtl8821ce-dkms-git
inxi or uname shows you which kernel to install / use
and change XX to your kernel-no. (e.g. linux58-headers)
after this…reboot 