Alright, so you need an avatar?
First off, here's what you do. Just get an image off Google or some other place and save it onto your computer. (If you need help on this, I can walk you through it.)
Then, you go to your User CP, and then go to "Edit Avatar." You'll be taken to a screen which gives you options of uploading a picture using its URL (which you won't need for this instance), and another that gives an option of uploading one from your computer.
There will be a blank field and a "Browse..." button next to it. Click that button, and you'll be taken to your pictures (if not, navigating there is easy), and all you have to do is double-click the image you want to have as your avatar.
After you do that, text will appear in that blank field, and that's normal, and pretty much tells you that it's been selected. Then, just click "Save Changes" at the bottom of the screen.
Then your avatar will appear.