Help with Doll Sweater!

Hi! I’m really hoping someone can help me decipher this instructions! I’m still a relatively new knitter --and am not sure what is going on now with this neck shaping.

Here is the pattern photo of the sweater I’m making (without the cables)

Here is what I’ve got so far:

This is where I’m at in the instructions: End at right armhole edge (18sts). Bind off and join these 18 sts with 18 from back. It may be helpful to place a marker after the 18th st becaseu it is hard to see the wrapped sts. (I did this on the front, right before the bound edges) --Do not cut yarn. Then work 24 sts from back.

Ok–so I ended my 18 stitches (they were by W&T --I understand this was creating the flap) at the armholde edges. And then I bound them off --but how do I join them to the 18 sts from the back (I’m assuming were my middle finger is?). Maybe I wasn’t supposed to bind them off, but rather do some sort of 3 needles bind off? I’m really confused here!! Please help!
Amy McDaniel