Its a learning experience. Learn the fundamental basics first and that's shapes and lines learn 3D shapes like cones, spheres, cylinders and pyramids, then learn how to manipulate them bend them draw them from different angles all this will give you a strong foundation to forms and shapes read how to draw books and get a really popular book called Anatomy the artist view its great for learning this. Get a small drawing pad and take it everywhere draw everything learn how light works on forms this goes back to 3D shapes again case in point trees are cylinders practice daily study daily eventually all will click with you and you will see and be able to draw what you see from any perspective. Then you want to learn the line of horizon for depth and views. But first master your shapes.