Armhole and neck Help

How-to Questions
1

I’m making a sweater shawl and I’m to the armhole part.
I just finished the left front arm hole and now it tells me to place remaining stitches on holder.
Then Right Front Join yarn in.

Do I cut the yarn from the Left side and then start working again on the RS? and if I do there is no extra piece to join into.

2

Yes, cut the yarn and leave a tail. Then use the yarn to work the other side. Just start knitting with it, leaving a tail, and you can snug it up later.