Things to start out doing would be getting something to dj with, aka a midi dj mixer, or CDjs depending on how much you wanna spend. Next would be a software for DJing if you are going to dj with a computer, some good virtual dj software would be NI Tracktor, or Serato.
Then you can watch you tube videos to teach ya, and then apply that stuff to your new gear. Then get good at it.