Emilee, Cassie gets my point. One side of a grey card is 18% grey which is useful for setting both white balance and correct exposure, the other side is white which is useful as a small reflector and to set white balance and the white point. Grass is green, and any shade of blue sky is blue! Green and blue are not good references for setting white balance.
As far as 9 focus points being able to quickly and accurately focus, this was taken with a Rebel T2i (your T3i is newer but virtually the same):
Raptors are very fast! This one was coming almost straight at me and it was only in the air a couple of seconds. I might be mistaken but looking at your web page, I don’t see any subject that moves at even half the speed of this bird!
Photography is a mix of art and science. It is a lot easier to do the art if you understand the science. That includes understanding how your camera works and not just what the camera settings do, but why you would want to use a particular setting for a specific shot. A rebel T3i is an extremely capable camera and shooting a posed portrait in daylight does not tax its capability at all.