Welcome to the boards! What you are wanting to do is create a signature.  This will be shown at the bottom of all of your posts. From a computer:  Click on your name in the upper right-hand corner of the screen and in the drop-down menu click Account Settings.   Then you will click on Signature and this will allow you to edit it. From a smartphone:  Click on the three horizontal bars icon at the upper right-hand corner of the screen and then click on Account on the menu, and then