Help with this Drops legwarmer pattern?

I think I’ve heard other people say they have some trouble sometimes with the Drops patterns. I certainly do. For instance, I’ve been searching for a different sort of legwarmer pattern, something fun and pretty besides just ribbed. I found this pattern at Drops but it is immediately confusing.
Anybody understand this?

The link is below but here is where I get confused:

Cast on 38 sts (incl 1 edge st each side) on needle size 9 mm with Eskimo. Knit 3 rows (1st row = RS) and P 3 rows. At the same time inc 1 st in the 16th st and 1 st in the 18th st on the last row (= 40 sts).

Wait, maybe I’ve got it. But to clarify: the increasing in the last row would be in purl. And I’m increasig into the 16 and 18th stitch. Maybe it’s easier than I thought. Also, WHEN THEY SAY (incl 1 edge st each side)
does that mean the cast on of 38 sts already has the 2 edge stitches in it, and those are what? done in garter st? knit. right?

here’s the link:

Sorry for so many questions! Thanks for your help.
What do you think of these? They are knit on Size 13 needles, that’s really BIG.

It sounds like you’ve got it. Increase on the purl side in the 16th and 18th stitch on the last row.

As for the edge stitch, it sounds like it’s already included in the 38 stitches you cast on. The first 3 rows are garter stitch so just for consistency and ease when seaming at the end, I’d suggest knitting the first and last stitch of EVERY row. That way at least all of your seaming stitches will be the same.

Just looking at the pattern…It would probably be very easy to change this to knitting in the round and then you could avoid seaming altogether. Just a thought!

Hey Knitqueen! Thanks much, I didn’t get a chance to come back til now. Appreciate the help. Yeah, funny a lot of legwarmer patterns I’ve been looking at have the seam up the back. Wonder why. Now, I just have to find the yarn for these!