acccessing wifi with bluetooth

Can you give us a bit more here.

This system offers WiFi support via the AirPort card it has inside.

This is an older system which does not offer support for the newer WiFi standards so it could be its just too old a system. Do you know what WiFi standard the access point (AP) you are trying to connect to offers? It will be 802.11n it could be 802.11ac being the newer standards.

On top of the WiFi standard there is also signal encryption. Like WEP and WPA, again depending on what the AP is expecting your system may not be able to offer the needed encryption method to be compatible.

Also can you explain why you also asking about Bluetooth here as well.

It maybe time for a newer system here.