Correct lighting is the key to all photography, even with modern digital cameras. [photography lighting]
Bright sunlight will cause over exposure and often it is better to avoid taking pictures at the peak times during the day all together.
With the automatic setting a camera will make a lot of assumptions and once you understand how that works you will be able to work with it rather than against it.
Switching to manual is easier for the more experienced photographer but for someone new automatic is so much easier.
Practice really does make perfect, as it is only as you use your camera more often that you get used to its varying abilities.
When choosing what to focus on avoid anything with an area of bright light, where possible. It is the difference between the very dark and the very bright that will confuse the ‘automatic exposure in a digital camera.
If you have pictures where people appear like ghosts and everything looks very strange then this is the probable cause. This is much better than it used to be, for most people having a digital camera means taking a lot more photographs because any duds can be removed and nobody needs to know.
So the chances of an overexposed picture is much less and also with experience you will learn to notice when the light isn’t that great and also remember the time when you had to delete some that were over exposed. Ultimately it is all about experience and that comes in time.