Another motif question

so I am trying my first motife, and I have a grid. I thought I understood but it is NOT working. I think the whole thing is JUST knit stitch, so how do you follow the grid and change color when you are changing colors on the right AND wrong side?? I have random stings strung all over both sides!

Knit on the right side and purl on the wrong. You don’t have to make it in garter. If the rest of the scarf is garter, you can make the motif only in stockinette.