Pic next to post?
 

How do I get a Pic from my gallery to show up when I post a thread?

You don't....just Invite any users to visit your gallery by clicking your user name.

Are you trying to use a gallery pic as an avatar?

Yes I am trying to use one as a avatar....

When you go in to edit your galleries there is a button/link to set any image as your avatar. I looked at your gallery and I did not see any pics that would make a good avatar, they would be too small to see anything.