Arch linux comes with nothing because it expects you to:
A) build it your way from the ground up
B) solve your own problems as they will be many.
Luckily solving problems in Arch is super easy because Arch linux has THE BEST documentation out there. Most questions can be answered on their wiki. The wiki entry for wireless can be found here:
https://wiki.archlinux.org/index.php/Wireless
If you are looking for something that will work out of the box more often, try Debian.