New member saying hi! (60D)

Yeah I have to keep practising with the new camera, but I have yet to find a reason for the under exposing. At the moment I only have the prime, but I'm planning to buy Canon EF 70-300mm f/4-5.6 IS USM or Canon 70-200 f4 L, or then some wider angle zoom. What do you think of those objectives?

tymevest: Amazing pic, what did you use to shoot that? In my pic the cat is yawning too