Pattern Trouble

I’m trying to make the Begonia shawl and im unfamiliar with “picking up” . The pattern literally says “k3, pick up and purl 88 stitches along the side of the piece”, But how do I do that if I still have my work cast on the needles? I’m so confused, please help!

Here’s exactly the first paragraph:
Cast on 3 sts, using the provisional cast on method.Work in garter stitch
until you have a total of 88 garter ridges.
k3,pick up and purl 88 sts along the side of the piece(1 st in each garter
ridge ),pick up and knit 3 sts from cast on ridge.
Now you have a total of 94 sts:3 selvage sts,88 body sts(pattern repeat
11 times),3 selvage sts.

Then it goes right in to the body. Im so lost.

Do you have the pattern? With the pick up those stitches should have already been cast off.