Help with instructions on preemie garter stitch set

[Claudette03]

Hello Everyone. I am working on the Bernat Baby Set in size 3 mos. I just completed the sleeve and I am not sure I understand the next set of instructions.

Next row: (RS). Cast off 26 sts. K5 (5-5-9-11-11) (including st on needle after cast off ). Turn. Leave rem 11 (13-15-17-17-19) sts unworked.***

I got that part done so I have 20 stitches on my left handed needle and turned.

Back: 1st row: (WS). K5 (5-5-9-11-11). K18 (20-23-26-29-34) from left front st holder.
Knit 2 rows.

Okay, so I knit 5 on the wrong side as instructed. And, it was the first 5 on my left needle. Now it says K23 from left front st holder. So, does that mean leave the other 15 stitches still unworked? Was knitting those first 5 correct (I still have 20 stitches on my left needle). Where do I knit those 23 from exactly? I have my stitch marked and I also put a stitch holder in the side 23 stitches.

Sorry if this sounds all over the place. Guess I am just not sure what exactly to ask...

Thanks everyone!