Hi Joe, and welcome to the forum.
Just to recap: in your "Edit Profile" section, the left side-menu will have "Edit Avatar", select this.
Once on the "Edit Avatar" Page, you will have three options:
No Avatar
Custom Avatar (max. size is 100x100 and/or 100Kb in size)
Pre-Defined Funny
Seen in this order.
It does sound like you've gotten to the right area, but I suspect that as a new member, there may be a short time period before the Custom Avatar becomes available to you.