The wireless connection in plasma should look similar to this
From which you should be able to select a network to connect to, and should be prompted for a password if/when needed.
Your wireless card seems to be inoperable at the moment.
Does this happen to be a dual-boot with windoze?
This card should be working out of the box.
But in situations where windoze was not fully shutdown (fast start enabled = hibernation instead of shutdown) it would not function.
Example related thread