There are hubs on this but a scarf is the simplest thing to knit for a new knitter.
If you want to knit without a pattern work out a tension swatch so- cast on say 20 stitches work 10 or 20 rows in the pattern you want. Now from this you can calculate how many stitchs you need to cast on for example if you want it (the scarf width) three times as wide as your sample swatch cast on 3 x 20 = 60 stitches. The amount of stitches you need will vary with the thickness of the wool and needle size that is why you need to work it out to start with or follow a pattern. The yarn label will tell you what size needles to use.Most balls of knitting yarn will give you a guide as to how many stitches to the cm. so if you cannot be bothered to knit a swatch go by that figure as to how many to cast on. you can get away with this in a scarf but not with a fitted garment.
To knit a Scarf:
Cast on the required number of stitches,
knit until it is the length you want it to be
(do n't stretch the knitting when you measure it)
When you have a scarf that is long enough cast off.
If you want add a fringe to the cast on and cast off edges.
Still not sure : If you search on line there are lots of free knitting patterns.