Violet is correct, to put your name inside a picture you need to use a photoediting program, sometimes if you get a nice enough picture of your celebrity avatar of choice you can do it in Microsoft Paint, but most will do it in Photoshop.
As you are unsorted and most people request galleons for their work you're currently unable to buy one in the
Graphics Requests Forum, however, sometimes if you
Personal Message a member, and ask for one free they might be kind and do it. That is, of course, all assuming you can't do it yourself.
You then take the image saved on your computer and upload it, as Violet mentioned, to an Image Hosting Website ( Ex:
TinyPic ) it will give you a bunch of different links once it is done, you should take the one that says 'Direct Link for Layouts'.
If you have any more troubles or questions as this proceeds you can also
Personal Message me with any of your questions or concerns and I'm sure I can help you out
~Nick