Audacity Newb Here...

I downloaded what I believe to be an older version of Audacity, and I cant remove the vocals from a simple acoustic/vocal file. When I followed the video instructions, there was a window, I believe the mono/stereo option, that wasn’t available on the version I had, yet it was there on the video instruction. Can you tell me what the latest version of Audacity is and where I can find it? Thanks.

It may not be possible to remove the vocals on some tracks regardless of the version of Audacity.

Thank you!