look at the top of your screen where it says "DEFIANCE" (yes in all caps).
now, look a bit below it.
there is a thick black line that says "FORUM" "WHAT'S NEW?" "COMMUNITY BLOG".
now on the right side of this line you'll see a white rectangle with a magnifying glass by it.

this is a wonderful tool called a "search bar".
you see, these are used to find threads about whatever question is on your mind. pretty nifty, eh?