Circular knitting, sleeveless vest

I’m a beginning knitter, having made hats and scarves. I’m now attempting the Lanesboro Vest by Blue Sky Alpacas, shown on Pinterest. It’s done on circular needles. It is a raglan design (what was I thinking!).
I got thru the raglan part, now have to bind off some stitches, followed by backward cast on stitches, more BO and more backward CO. A note at the end said to “turn the work as necessary.” I don’t know when to turn the work. Is that referring to creating the armhole? :aww:
If anyone understands my question, I would appreciate some clarification. Many thanks, Lilly

Yes, sounds like the armholes and maybe this is a top down knit?

When you cast on in the middle of a row, you turn or switch the needles in your hands. The needle with the newly cast on sts will be in your left hand. Once the sts are cast on, the needle with the cast on sts goes back into the right hand and you continue knitting. That may be the turn that they’re talking about.

This video may help: