Baby Bunting

I’m a new knitter (I’ve only done a few projects). I have never casted on in the middle of a row before. So, I’m confused on how to do this. I’m making a baby bunting. And the pattern starts out like this;
Left Leg: (Flap). With MC, cast on 11 sts. With MC only, proceed in seed st until work from beg measures 3 ins. ending with WS facing for next row.
Next Row: With MC, cast on 12 sts. Pat to end of row. 23 sts. Place markers at each end of needle.

So, I’ve never casted on stitches in the middle of the work before, and I’m confused. :?? How do you work them. Do you add them on and then turn? I’d appreciate any help.

Edit: I usually cast on with a long tail cast on.

Usually when casting on in the middle of the row I use the backward loop cast on. There are others that would work as well (cable and knit on), but the backward loop is easy and fast and looks good in the end.

Videos in KH

:happydance: Thank-you.
I was stuck at that point.