Hi Vinoth,
There are many things to read on here and on the blog about starting to DJ.
You might start with buying some music or using some music you already have and loading some free DJ software on your PC/Laptop (like VDJ or Mixvibes Cross, both free to use on computer without controller) and just start playing around with it.
Then decide if you like to expand and pick a software and a controller and get practicing. Set some money aside to take the Digital DJ Tips How To Digital DJ Fast course and off you go.