Stuck on chicken jumper pattern

Hello everyone, hoping someone can help me out. I’m currently trying to make chicken jumpers following this pattern;
However I’m getting stuck when it comes to the ‘divide for neck’ part. Do I just follow the pattern for 11 stitches or the whole row?
Hope this makes sense and any input would be greatly appreciated x

Hi and welcome!
You’re going to be working one side of the neck first then return to the other side. So for now, work on the 11sts for side 1.