Okay, the searchbar is a wonderful tool that should always be used before creating a thread that deals with anything except a scenario that pertains to you specifically (remember personal promos/edits go in the video section). It is located on the upper left side of your window and is a textbox next to a scroll bar that says forum. It looks like this.
Now just enter your thread topic and press search. If some topics appear search around and see if what you wanted to post has already been shared or asked. If not post away. If it has then refrain from reposting please.
Have and enjoyable day.