Installation Guide/Configure Pacman
From ParabolaWiki
1 Configure pacman
Edit /etc/pacman.conf and configure pacman's options, also enabling the repositories you need. See Pacman and Official Repositories for details.
Also consider using Pacman2pacman, a peer to peer package system, in order to reduce load on official Parabola servers.
1.1 Systemd
If you are running systemd rather than OpenRC, make sure that the nonsystemd repo is NOT enabled.
1.2 OpenrRC
If you are running OpenRC rather than systemd, make sure that the nonsystemd repo is enabled.