Check wifi’s working
Or for usb wifi:
dmesg | grep usbcore
… and hopefully it’ll say the new interface is registered.
Check if a wifi interface has been created
Assuming it’s wlan0, bring it up with
ip link set wlan0 up
Error messages probably means your wireless chipset requires a firmware to function. In this case, check the kernel messages for firmware being loaded
dmesg | grep firmware
iw doesn’t do wpa/wpa2. wpa_supplicant does everything. iwd does everything except WEXT encryption.
Get the link status:
iw dev wlan0 link
Scan for available points:
iw dev wlan0 scan
The connecting commands do not cover wpa2.