There are a lot of information in the Pseudonyms, Avatars, and Signatures section of the Membership Manual - it really would help you out to read the Community Membership part of the Manual from the beginning and then keep going. It answers many of your questions and will undoubtedly answer many...
Many people look through DeviantArt or similar sites, and if they find an image they like, they write to the artist to ask permission. So that's one way to do it!
Hi there, and first of all: welcome to Tar Valon!
Secondly, all the information about how to join the community and progress through its ranks, eventually becoming a Senior Member can be found in our Membership Manual. I'd advise you to start reading the first section, Visitors, and go from...