You already got solid advice from Marked4Destiny and Dragonflyfla. Pencil mileage is key. Get a pack of cheap 2B pencils and a notebook from you local Dollar store. I say Dollar store, because you are asking for cheap supplies. Carry your notebook everywhere you go. Draw everything and everybody.
Some tips are:
1- Draw what you see, not what you think you see. Look at the subject more than the drawing.
2- Think in terms of shapes, not lines. Example, don't draw the outline of a nose. Instead, draw the shape, shadow, diffuse light and highlights around the nose.
3- Use light construction lines at first.
It's my strong belief that nobody is born with artistic talent. It's a talent that comes after many hours of practice. Have fun!