If you want to use a professional DJing solution, then Serato Scratch Live is one of the most popular choices of software. If you were to DJ professionally, it would be a great advantage to you to use an audio interface controller. However, if you are just learning, you can use Serato without an interface controller. An interface, when connected to an audio DJing program, helps control various functions that otherwise require you to use the mouse and keyboard to control. However, you can use Serato without an interface, using your mouse and nothing else.
Launch Serato from your Start menu.
Click "All" in the file browser window to load your entire music library. Select a song from the list of options. Click and drag it into one of the empty decks at the top of the screen.
Wait a few moments while the BPM of the track is calibrated.
Click the "Play" button to begin playing the track. Locate another song you want to mix it into and drag it to the other deck.
Click the loop button on the second deck, then click "Play." Click and drag the volume level sliders down on one track, then drag them up on the other track. Do this incrementally until you have mixed the tracks. Stop the first deck and unloop the second deck. You are now using the basic functionality of Serato without an interface.