Hi there!
The sandbox is a separate site used to keep drafts and works in progress. (There are instructions on how to use it, on the front page.) Create a new page there named after yourself (so people can tell to whom the page belongs), and you can keep any material you write for the site there. The idea is that you can get a feel for how wikidot coding works, and when you're ready, show the sandbox to other people in the IRC chat and/or the drafts forums for feedback. In-progress stuff is not allowed on the site and full drafts should not be posted to the forums, so the sandbox page is really handy. All you need to do when you've got something finished and ready for critique is post a link in the forums or chat!
If you'd like to show some of your art to other people on the site, make a new thread in the Fan Work forum. If people like your art and you have enough of it at consistent quality, you might get your own art page on the site!
Let me or another staff member know if you have any further questions. Welcome to the site!
