If you have a point and shoot digital camera, you may not be able to adjust those settings. What kind of camera is it? Some cameras will also allow you to adjust the focus point in the frame. I do that sometimes when the camera wants to focus on the wrong thing.

The F-Stop controls the depth of focus. The higher the F-Stop the deeper the focus will be. If you use a low F-Stop, the thing you focus on, typically the closest thing to you will be fouced and anything else will blur away. This also helps to sharpen the object you are shooting and make it stand out more in the photo.