The body you have is fine and gives you access to a very nice range of lenses. A very cheap and good lens is the 50/1.8. $100 new, sharp and very nice. I can pretty much do almost everything with a 50.
Just go with that to begin with, once you find your pace and way of shooting it will come naturally what you need, be it a manual camera, more EOS lenses, medium format and whatnot. The biggest mistake that most (myself included) make when starting out is to constantly buy all sorts of equipment, bodies and lenses looking for the next great thing. Take it easy and you'll waste little money buying/selling things.