Arch Linux install: wlan0 is up but not connecting to Wi-Fi

I'm trying to install Arch Linux on a Lenovo Harman/Kardon IdeaCentre, and I can't start a working internet connection.

$ ping archlinux.org
ping: archlinux.org: Name or service not known
$ ping 8.8.8.8
ping: connect: Network is unreachable

This is after I have connected to my home Wi-Fi. I tried using an external network interface but that did not work, I also tried running

$ systemctl start dchpcd@wlan0
Job for dhcpcd@wlan0.service failed because the control process exited with error code.

I have watched a couple of videos and nothing seemed to help. I tried running ip link set wlan0 up but that didn't seem to do anything. I have rebooted several times and that also didn't help. This is what comes up for wlan0 interface when I run ip link:

4: wlan0:  mtu 1500 qdisc noqueue state DOWN mode DORMANT group default qlen 1000
    link/ether 11:22:33:44:55:66 brd ff:ff:ff:ff:ff:ff