Help! probably an easy question for those with experience

i am knitting a pair of striped booties for an infant. i have finished shaping the heel, and am now attempting to shape the instep, but the directions are starting to confuse me. as of now, i basically have a piece that looks like an overturned table. the next instructions tell me: k5, pick up and k8 evenly along inside edge of heel, k12 sts. holder, pick up and k8 sts. along inside edge of heel and k5 from holder. the following step is to purl one row. my issue is i’m not sure i understand exactly how i am supposed to"pick up" these stitches. if my piece looks like an overturned (upside-down) table, how do i get back to the point of knitting straight across in order to purl? thanks

By picking up stitches along the side of the piece you just knitted, you’ll have them to purl the next row. Go look at the bottom of the page for the video on Picking up stitches. Your piece will be a little curvy for a couple rows but it can be done easier than visualizing it.

sue