I suggest you go to the bookstore to buy a sketch plaster geometry and copy it at home. There is a problem. Then you can watch the video. What can I do to get better results? When the geometric shape of plaster is drawn to a certain extent, let the back door in. Then still life-plaster portrait-portrait. The same method. You can ask me any questions. You will encounter many difficulties in your study, but you must not give up. But the best way is to attend a training class. With the guidance of the teacher, your efficiency will be greatly improved.
I believe it will succeed.