What would be the best software to mix tracks together ?
I always come up with nice Idea of mixing songs together , and I'm PRETTY sure it would always come out awesome.
But I just don't know how to use it or what software to use.

Lets say like C.R.E.A.M. from WuTang and I need a Dollar from Aloe Blacc mixed together to make D.R.E.A.M.
One part is music from 1 song, the rest is the lyrics from the other.

LMK PLEASE
thanks

It'd be tricky to pull the vocals out without all the other music. You can always record one section of music and loop it but extracting a track requires sophisticated software. Melodyne can do this. There may be others:

http://www.celemony.com/cms/

Any recording software can produce the rest.

Yeah pretty much what he said. Basically trying to pull vocals out or music out of a produced song is almost impossible and you will definitely have some quality issues as well as depending on the array of frequencies for either would be almost impossible. Your best bet would be to hope that the artist released instrumental versions (which some do) or that another musician recorded the music for one or the other (which is common for some music that people ilke to cover)