It is a very simple scarf and you probably do not need a pattern for it, unless you are a beginner. The ribbing makes it squishy and the sides do not curl.
This is a one size pattern for babies or toddlers but you can easily cast on more stitches and knit more or less rows depending on the dimensions that you are looking for. Gauge is not crucial.
You will need approximately one skein of DK yarn (100 g / 225 m) to get a scarft that is about 4 inches wide and 28 inches long.