How does understanding DNA help to understand ourself

DNA is basically the building blocks of human life, these small things are where all of our visual looks come from, but not only visual sometimes DNA can bring some diseases that their child might have when they are older, like for example some families have a diabetic DNA high makes their family and themselves have a higher chance to get diabetes which is not really relevant. DNA can be really long in the human body, and it lies through the human body, most of the time it's lays in the cells, well at least from my background knowledge. The DNA was formed when the baby is born and it might vary if you get different DNA structure from each of your parents.

       It apples of who you are because it is what you will be like. Like I said DNA can carry many traits that some of your parent might have when they were younger and you could adopt that traits into your life. It depends on what you are like, and there is no one in this world that will be exactly like you because of the DNA.

Some of the questions I have is how does the DNA conjoined to each other? And that's all the question I have and I hope I can learn new things about DNA.