HELP INFO PLEASE

I am a NOVICE I am fumbling my way around with backups/copying/creating my existing web site (not built by me). I am with IPOWER. I want to do a backup of my current website - advice given to create a Output Directory (I guess in SmartFTP). Question is HOW please advise - do i create it in my public_html or somewhere else?? PLEASE SOME ONE HELP, thank you.