Sweater - unworked stitches question

I am knitting a preemie jacket (looks like a sweater) that is worked side-to-side in one piece. I casted on 38 stitches and knit 5 rows. The next instruction is

Shape yoke

**1st row(RS) K25. Turn. Leave remaining 13 stitches unworked.

2nd row – K25

3rd and 4th rows – Knit to end of row.**

Repeat last 4 rows until longer edge (bottom) from beginning measures 41/2” ending with a 3rd row. Place marker at beginning of last row.

The next instruction is for the sleeve.

The instructions don’t say to put the 13 unworked stitches on a holder and it doesn’t make sense to me to knit row 2 then on row 3 to include the 13 unworked stitches. Am I reading this correctly? I also don’t understand what ‘place marker at beginning of last row’ means. How do I place a marker at the beginning of a row? Thanks, Nancy

The 13 sts will get worked on R 3 - ‘knit to the end of the row’. Then turn and knit all the sts agian on rows 4 and start over with row 1 where you leave 13 sts unworked and turn. So you knit these sts on 2 rows out of 4; that’s what makes the yoke top of the sweater.

" I also don’t understand what ‘place marker at beginning of last row’ means. How do I place a marker at the beginning of a row?"

You can tie a loop of yarn at the beginning of the row as a marker. A safety pin or plastic marker will work as well. It’s marking a place in the sweater for later directions.

The other responses answer all your questions but this one:

If you have 38 stitches on your left needle, then knit 25 stitches, you will have 13 stitches on the left needle and 25 stitches on the right needle. The instructions say to turn and knit row 2 of 25 stitches. So you turn and have 25 stitches on the left needle and 13 stitches on the right needle at the beginning of row 2. At the beginning of row 3 you will again have 38 stitches on the left needle.

So there is no need for a stitch holder, your needle serves as a stitch holder for the unknit 13 stitches for these 2 rows.