Hi Pami,
Welcome again to MM.
Click into the link in the upper right hand corner of the forum that says:
My Controls. There are a lot of things in there going to the left hand column that you can do/set. The categories are: Messenger (where you'll send and receive PM's), Subscriptions (where you can set up notices on posts), Personal Profile (this is where you can choose an avatar (or load up on of your own in the 'Edit Personal Avatar' link), and Options (where you can set up email and board settings for yourself).
Check all these things out and let me know if you need assistance.
Cheers
~Cleo