Sorry... Very confused with this! Can't see any files

My apologies for the basic and stupid question, but in order to see files on my Ipad2, must I first copy and paste files from my computer to the external hard drive? 

I thought that’s what back-up was for, but apparently backup is a hidden directory, so I can’t see a thing.

Yes. You need to have the files in the MBL. Backups, as you have guessed, aren’t files that wd2go can use.