Apple is easy thing to draw. It start from basic round circle shape then you can add some tweak to the lines. Lets do it!
1. Sketch a circle with pencil
2. Add curve to lines, make a stalk and leaf (optionally)
3. Trace desired line art
4. Clean it by erase the pencil or hide sketch layer if you are using software
5. Fill basic color
There are many varieties of apple. You can or start again from new shape and different color. Have fun!