To start, you press the R key. This is also the restart key. Remember, the ball will go in different directions every time you play! So just experiment on the designs it makes and stuff. To put the pen up, you click pen up, which will appear in the bottom left corner. To put the pen down, you click pen down, which will be in the bottom right corner.
This was a very fun (but challenging) project. It doesn't take too long when you know what you are doing. (I didn't at first XD) But I hope you enjoy this, it was very challenging to make so, have fun! Thx!