Julie, I have been meaning to comment and kept forgetting, this is BEAUTIFUL for a first try, and even MORE impressive to me that you achieved this on the backside of Canson. I personally don't like canson at all. When I first started using pastels, that was all I had like you didn't know any different, but the sanded papers make the biggest difference in my opinion. If you go to the fine art store's site, you can order a sampler pack of several different papers. It might be worth it to see what suits you the most.
I can't wait to see what you do next!
Here is where you can go to get that sampler pack.