It's really good for a first attempt! Some friendly suggestions: leave the whole bottem layer for the background so you don't have to worry about coloring around your pic. If you really need something else on that bottem layer, still color in the background first. Keep working at digital art! It takes awhile, but you do get used to the... "slipperyness" of it eventually. You clearly have a lot of important basics down from tradional drawing; keep experimenting with this new medium.