|You should only be concerned with external and external port numbers if you are doing port forwarding and the only time you need to do port forwarding is if you are running an Internet server of some kind that is expected to process unsolicited incoming requests.|
It has nothing to do with setting up a wireless connection and is not needed so you are probably in the wrong place and can ignore port forwarding. BTW, there are about 64, 000 different port numbers that could be used and the first 1000 have very specific uses, none of them related to wireless connections.
All you need to set up a wireless connection is for both your wireless router and computer to be configured for the same security protocol and to know the necessary password to connect. If you have DHCP configured on the router and computer you don't even need to worry about IP addresses as that is done automatic.