HELP with arm hole bind off and cast on's on Vest

New knitter and having trouble figuring out armhole on vest. Pattern calls for Row 26 (WS) P12, bind off 14sts in K, P19; Row 27 (RS) K19, cast on 14, K12. I have torn out so many times and still can’t get it. Every time I try there seems to be huge holes and I cannot figure out how to cast on in middle of row. Please help me. Thank you

Can you tell us the pattern name and give a link if possible?

Welcome to the forum!
Yes, a link to the pattern is always helpful. Here’s a video for the basic idea behind your pattern instructions. Switching the needles in your hands as shown in the video is the key to make this simple. You can the use a knit cast on as shown or a cable cast on if you prefer.

You should end up with one hole which is the armhole.

The pattern is “Magnum Reversible Vest” by on arm hole Hope that helps you to understand what I can’t seem to get. Thanks

the pattern is “Magnum Reversible Vest” by Thanks

Is this it? It is a paid pattern?