Well, the most important thing when learning to paint is: do not get discouraged. There will be stuff you don't like, stuff others don't like, and those that will tell you so. You need to remain positive. I think this is a great effort, so keep on painting and enjoy yourself. All the best with your painting.
Some ideas..... first, and easy, do not do this bases, look in other painters and watch how u can improve the base is easy and is very important. Paint the rocks on the base and the grass.
The colours on the model..... put one colour and then more lighting lines, u could note that the effect gives realty to ur model. Take care of the small details.... and thats all. Bye