You are now signed in to the demo account. Feel free to push all buttons you can find to fully test out this site. Once you feel confident it offers what you want, you can sign out again and sign up for your own account.
Note though, that this demo account is open to everyone, so after a page refresh your tweaked values may be set to someone else's idea of a funny try. It might also give you errors when you want to change something, while someone else just snatched it away under your feet :)