Nice start! At the moment, I think the most you need to work on is composition. Before starting an enviro, try to experiment with different ways of putting it all on the paper. Check out the masters' landscape paintings, lots of them. Composition is difficult to explain but it's rather intuitive, you will soon se which elements fit well in the picture and which don't.
Also, when copying from life or from a photo, try to set all things in the right place and proportions before starting to render. For example, the bald man in your last post has a really small craneum (or really big face), and small eyes compared to nose and mouth.
Anyway, keep posting your work! you've got a good grasp on colours, and your pieces have a lot of potential!