The first step to taking better photos is to take your camera off auto.
Here is a breakdown of these settings and how they work together to create a great picture. Every camera is a little bit different and includes auto settings for scenes. However, if you can learn to master Manual, Aperture, Shutter Priority settings, it will be easier to create great photos more consistently.

Aperture - The size of the opening.

A larger opening lets in more light but creates a shallow depth of field, meaning the background is less in focus. This can be nice for portraits but not ideal for scenic shots.
A smaller aperture lets in less light and keeps more of your frame in focus.

Shutter Speed - How fast the lens opens and closes. Faster shutter speeds will freeze motion and let in less light.

Ideal for brightly lit scenes.
Slower shutter speeds let in more light and blur motion. Using a slower shutter speed will help in low light situations, but can blur your subject. This makes for beautiful waterfall shots but not so much when you want your subject in focus. Using a tripod is beneficial if a slow shutter speed is required.
ISO - The camera's sensitivity to light
100 ISO would be ideal for lots of light and 3200 ISO is used for low light situations.
A higher ISO can make your shots grainy.

These three components make up your exposure. The goal is to use the manual instead of auto. Start by using the aperture or shutter priority modes on your camera to get used to control each setting.  Once you understand how they work together, you can use the manual setting to control them all.