@menard, thanks but Im not sure I understand even what SMF is and that other stuff.
If you happen to have a cold dead fish around, could you kindly slap yourself in the face with it repeatedly?
SMF is the name of the forum software this forum uses (it's at the bottom of the page
If you want it simplified, we'll call it BadMovies Forum instead.
At the top of the front page of the forum (or, for that matter, any page on the forum), there should be some kind of link for your user profile, which may actually be called 'Profile'; if not, look for a control panel link.
Once you click on that, you'll see your control panel/profile with a set of links, usually on the left.
One of those links should actually read 'Account Related Settings'.
Clicking on that will show you a list of settings with your User Name, that can only be changed by the admin, and your Name, which is what is displayed in all of your posts, and you can change that.