You are confused most likely because it sounds like you have only ever dealt with home based WAP units. Such as Linksys, Netgear, etc.
Generally speaking, Cisco WAP's are setup and configured in much of the same way all enterprise Cisco equipment is programmed, though console cable, telnet, ssh.
I find many of the younger administrators that have no network configuration experience to expect that any kind of real configuration occurs in a GUI interface (cisco cna no where near useful as console).
If you have never configured a Cisco WAP though console before you will most likely finding it very confusing.
Lets start by getting you into the GUI by manually configuring the ip address (assuming you dont have dhcp)
Connect a Cisco Console cable (if your not sure what it looks like google it).
Once connected, depending on the default config it might ask for a username and password. If it does it will be either "cisco" or "Cisco" for both username and password.
Once logged in type "en" It might ask for a password again, If it does its again either "cisco" or "Cisco" don't use quotation marks.
Now type in console
conf t
interface BVI1
ip address <ip address you want to use> <net mask>
(ctrl+z on keyboard)
conf t
ip default-gateway <yourgateway>
(ctrl+z on keyboard)
wr mem
hope this helps, should now have the ip address you set. LEARN CONSOLE!