Help please ? Mac OS High Sierra 10.13.6

I downloaded Audacity 2.3.0 and i tried to remove vocal i imported the mp3 audio file and i followed all the instructions which’s the drop down split stereo to mono is greyed out and i can’t click on it . i took screenshot …help please ?
Screen Shot 2018-10-10 at 8.34.56 PM.png

Audacity has two built-in tools for vocal removal. Have you tried those? Neither one requires any further action (such as splitting tracks).

– Bill

Thanks for reply back, No I didn’t try anything yet and I never use audacity before, this this my first time and I don’t know how to do it. If you can send me a screenshot step by step I would be appreciated

Thank you

You apparently tried something.

Please look at this page in the manual.

– Bill