I have never been skiing in my life, well unless you count one time in Norway when I was so bad I came back down on the lift! I only want to try it for one day so dont want to go and buy all those puffy waterproof clothes you need. Im not sure you can do it in jeans can you.
You could probably pick up some semi-waterproof type bottoms pretty cheap )(cheap enough to chuck) just take some longjohn kinda thing for underneath and a fleece should be okay at this time of year. To be honest I dont envisage there being much snow.