You would cast on a multiple of 10 stitches, plus 1 more stitch. So you would need to cast on 11 stitches, or 21 stitches, or 31, or 41, or 51.....
(The number of stitches you cast on depends on how wide you want your item to be. So, if you want to make a scarf with that design, just cast on 21 stitches and knit for a while to see if it's wide enough. If it's not, then frog it and start over with 31 stitches instead.)
For this row, you would Knit 1 stitch, then YO, K3, SK2P, K3, YO, K1. Then, you would continue the row, beginning with the YO, K3, SK2P, K3, YO, K1 over and over again until you get to the end. If you only cast on 11 stitches to start with, you wouldn't repeat that part at all, because you would be finished with the row. If you cast on 21 stitches to start with, you would only repeat that part one time.
You would cast on 4 stitches, or 6, or 8, or 10, or 12.....
(again, depending on how wide you want the item to be)
For this row, you would Knit 1 stitch, then YO, K2tog over and over again until you get to the last stitch. Then, you would knit that 1 stitch.