Welcome,
Each of your deviation page has a button labelled "Add to a Group"
after clicking it you have to pick a group (either by picking from the list of ones you already added your deviations too or by typing a group name and picking a correct folder to submit to. Then you click "Done" and we as admins take it from there by approving your art into our group.
Have fun sharing your characters and their stories with the rest of us.