First, you should know which is your dominant hand. Your dominant hand is basically the hand you right with. So are you a righty or a leftie?
Your dominant hand shows your life and its direction throughout your life. The opposite hand shows your traits and what you're born with.
There are a few major lines of the palm. This may include the life line, head line, and heart line. These lines aren't hard to find, they are the three deepest, horizontal lines on your hand.
The lifeline will tell you about your health, well-being, and changes in your life. It is located near your thumb and it is the lowest deep line you will see. The head line will tell you about the way you learn, communicate, and your need to know something. This line is located inbetween the other two deep lines. The heart line will tell you about your emotions. It is highest line out of the three.
There is also a fate line, although some people may not have it. This line can tell you about your destiny, or important points in your life. It is a vertical line in the middle of your palm.
Look at the lines on your palm. Does it collide with other lines? Is it long? Short? Deep? Broken? Does it have other markings on it? Shapes on the lines? The traits of the line on your palm can have different meanings.
I have only explained the major lines. But there are other parts of the palm to read, such as the children lines, your health line, the mounts (of Mercury, Apollo, Saturn, and Jupiter), your health line, etc.
What are the weird markings on your palm? And I'm sorry but you can't change the lines of your palm to change your future. Our palms don't determine our lives, well that's what I believe at least.