1.The Junior member part just means your a new person on this forum. When you have been here for a longer amount of time, your status will change to Senior member, etc.
2.Friends list is basically for people you communicate with on a regular basis. As in, if you want to send someone a Private Message. You can just go to your friends list, find the person you want to talk with and send a message.
3. Go to your profile, and add avatar. You can pick a picture from your computer to have for a profile picture.