A little help understading

Row 1: knit across (wrong side)
Row 2: Knit to last 11 stitches. Wrap next stitch, turn
Row 3: Purl to last 11 stitches. Wrap next stitch, turn.

what does it mean wrap next stitch and turn???

You are working what is called short rows here. You only work across part of the stitches and then turn the work like you would at the end of row and work in the other direction. When you do this it tends to leave a little hole where you turn, the wrap helps to fix the problem.

If you are knitting (row 2) to wrap you do the following: With the yarn in back, slip the next stitch purlwise, move the yarn between the needles to the front, then slip the stitch back to the left needle. Then turn the work by exchanging the needles in your hands like you do at the end of the row. Then move the yarn to the purl side between the needles so you can purl.

Purl your 11 stitches and then wrap like this: with the yarn in front slip the next stitch purlwise, move the yarn to the back, slip the stitch back to the left needle and turn to go the other direction. Bring the yarn to the back between the needles before you begin knitting.

Wrap and turn is used for making short rows - not knitting all the way to the end of a row. The wrap wraps the yarn around the slipped stitch which you knit together when you get back to doing long rows, and turn is just like at the end of a row when you turn your work. There’s a video on the Advanced Techniques page that shows how it’s done.