How long have you been using WordPress, or what version number of Wordpress did you start with?
Six months or so. 3.3, I believe.
What topics about WordPress would you like to learn most about?
Child Themes. I've been trying to dissect all the parts of the new 2012 theme.
What is your experience with using existing Wordpress plugins or creating your own?
I am not a PHP Developer. But I am learning.
What is your experience in building custom Wordpress themes? Tell us more.
Slowly but surely learning to customize themes.