Yes, it does mean to get yourself ready or to get organized. It is an interesting phrase. If you say "pull yourself together" it tends to mean that you should get your emotions under control (or to snap out of a state of drunkenness). "Get yourself together" might also have this meaning, but "pull yourself together" would not have the meaning of "getting organized" or "getting ready."
These are very common phrases so it is good to master them. Thanks for bringing it up.