I may have a misunderstanding of the global idea of what the World of Minecraft client is supposed to do, but I only want it for now to work on singleplayer, but when I press shift for example to go faster, nothing happens....

I'm open to anything, but maybe this has something to do with macs, maybe it has something to do with...oh well I have no idea, I'd love any assistance.

I already did the video tutorial way of installation, and everything went well. Any ideas?