What mode do you have your camera set in? Try Closeup mode for the close shots and try Landscape for shots like the first photo above showing the row of flowers next to the fence (buttons on top of camera near shutter button).
Make sure to try the scene mode (then select "flower" and take some shots then "closeup" and take some shots).
Scene mode is selected using the mode dial on the back of the camera. Just keep trying different things till you find what works best for you. You do have some exposure compensation adjustment by using the joystick in the center of the mode selector dial. Try that with some shots also.
