Beat Mapping, Where do I start? Options

[yojames]

I am trying beat mapping for the first time. I am attempting this on a region with a full song. After it has been "analyzed" I try to start my adjustments when the alert "Song start must be at 1 1 1 1 for adjustments". I have tried moving this region all around. I don't understand what to put where so that I can make my first adjustments. There is about a single bar of silence, then a short vocal intro, then the drums start around the 3rd bar. Thanks for any help.
James