Macro mode - This setting allows you to stand just inches away from your subject. It is good for taking close-ups of flowers, insects or other small objects. Macro mode decreases DOF, allowing you to focus on the smallest details. Do not zoom in or use flash when using this setting.
Aperture and Shutter speed - Aperture is how wide the shutter opens. A wide opening, like f/2, allows more light to enter than a narrow opening like f/22. A wide opening decreases DOF and a narrow opening increases DOF. Shutter speed is how long the shutter stays open. A slow shutter speed, like 1/4, allows more light in than a fast shutter speed like 1/1000. Using a slow speed can catch motion and using a fast speed can "freeze" motion.
These two settings work together. To prevent over and under exposure, a wide aperture will cause the speed to be fast and a narrow aperture will cause it to be slow. When using a slow speed, you are at risk of camera shake which can blur your picture. To prevent this, you will need to support the camera with a device like a tripod. If you don't have a tripod, you can place the camera on a flat sturdy surface. When you don't want to use a tripod because of its inconvenience, hold your elbows close to your body, hold your breath when pressing the camera's button and don't let go of the button until the shot is finished.