This pattern has instructions for DK or worsted weight yarn. Gauge is not crucial, and you can easily knit a longer cowl if you wish; the pattern gives the multiplier.
DK uses approx 150m of yarn per colour; worsted uses approx 170m of each colour.
Three different edging options are offered within the pattern with links to online tutorials and youtube clips if you are unsure how to work some of them. The edgings are: garter stitch, tubular rib, and icord.
The pattern works best with two quite different yarn colours of the same weight and fibre type.