It's not a problem :3 Basically there's a 'Join Our Group' button at the top, click that and you're automatically in the group
You need to be a member to submit into the folders, once you're in then go to the folders and look until you see 'Fanfictions', there should be a 'submit to this folder' at the top right click that and then select what fanfiction you'd like to submit ^_^ Hope that helped :3