A "Contributer" is the person that gives prices for contests and can edit some content of the group.
A "Member" is the person that only submits works to the group's gallery.
You can also be a "Watcher", just go to the group's page and click on "+deviantWATCH".
Considering your situation, I suggest you to become a member or a watcher, but choose the rank you prefer the most.
I hope I could have helped you XD.