Replying to Question for you amature DJ's

I've been curious about just doing some mixing and stuff as a hobby. I need some ideas for good mixing/DJ programs that will be fairly easy to use.

Also is there a way to separate vocals and the backtrack from songs? Like I know a lot of DJs put together mixes with different backtracks. Or do you get the backtracks separately?

I might be using wrong terms too. So if you can help, and need me to clarify what I'm talking about just let me know. Thanks.