Cast on 34 st. If these 4 rows repeat to make the scarf pattern, then make a chart. On a scrap of paper put down-
Row2 (WS)-Knit (these 2 knit rows will form one garter st ridge)
After you complete a row, put a slash mark beside the column to keep count. And put a safety pin on the right side, to make it easier to tell which is the RS vs WS. Both these things make it a little easier to remember where you are on a pattern if you set it down & come back to it.