Could use some more info. If you try to play some kind of sound file using a console it may give you an error message that you can post. For now some obvious things to check is that you don't have the sound muted. For some reason I've had a couple of fresh installs that have things muted to begin with. Also you might need to configure your sound card, type alsaconf into the console.
As for the IM problem, you also need to be more specific. What instant messanger did you try to use? (there are multiple ones) What exactly is happening when you try to use it? Try starting it from a console, same as with the sound problem, this may give you some error messages.