Start from bottom edge of the picture and first find the four grey metal wheels. Can you count them? Stretching above the wheels is a slim horizontal line. At each end of this, to the far left and right, are the small rounded shapes of the black buffers. These act like big metal cushions, should the train run either backwards or forwards into anything by mistake.
Above the back wheel on the left is the back of the train. Inside here is the coal box. Trace up to feel its shape. Can you trace the slim raised outline of a rectangle, this is a decoration and it's coloured yellow. On a real steam train it would shiny brass.