please follow arch wiki beginners' guide
once you can boot on your freshly installed arch and you are connected to internet, run the post-install.sh script
You can run it as root or as a regular user but this user have to be a sudoer
the script will propose you functions to automatize some recurent process
This script is only my note taking along my discovery of Arch Linux install (after a year using Manjaro
It's not fully tested, and may fail at some points, feel free to report bugs, i would be glad to help, or fixe them, if i can/have the time/etc.
Feel free to fixe bugs, add features, with pull requests
This script reflect my vision of a an arch linux install, maybe not yours ...
This script only intend to install arch linux + plasma5 on my laptop only (gigabyte P34W v4) but it may also work for yours
You may want to read and follow the post-install.sh script instead of runing it :)