Hey, I'm Molly. :)
Well, apparently you do know how to post. Thats a start. :D
To get a signature, you can ask someone to make you one or you can make yourself one, if you have a graphics program. A signature is the picture that will always appear under every post you make - the pictures under the words I am typing.
To get an avatar, just pick a picture of the JB and upload it.
How to upload:
Go to Community, My Settings (the purple gear in the toolbar of pictures above the forums) and click user settings. Then click user settings again (it will be a plus sign next to it) and find where it says avatar. Save the picture you want for your avatar to your computer to a place you can remember, and then browse and find it and hit upload, and then update. Same with the signature, except all you enter is a code that if you ask someone to make you a signature, they can provide for you to copy and paste in the text box that correlates with the word signature.
If you would like an avatar or a signature, I can make you one. Just tell me what pictures, and what it should say (on your signature)
Hope this helps! Glad your a member of JBF! :)