At first, mixing tracks may not seem so difficult but, if you want to create a real masterpiece, it may take several weeks or months. Real professionalism is achieved when the volume of numerous tracks is adjusted between each other. There are a lot of applications designated to produce quality mixing but they are also divided into professional that include the opportunity to record, produce and mix the music and applications that are used to create simple tunes.
The choice of DJ software depends on your needs and, considering them, you will see whether free software will be enough for you or not. To make the final choice, you will have a chance to try free trials or to consider the reviews of users on community websites or forums.