use your mouse to draw on your top left you can change the size of your pen or your eraser.On your top right you have a color pallet.You can select any color you want.If you wanna hide the color pallet there's a button on your bottom left to do it.If you want to unhide it just press the button again.Press space if you wanna clear everything of just click the button thats bellow the eraser button.
-a youtube video i found by OtoStartedProgramming helped me code the pencil. -rest of code from Lakenap (me)