You'll spawn with your cursor by the green flag. hold down the cursor for a minute, you may have move your cursor up, for the pen to stop. If you see the colors at the left bottom corner of the screen... You can click that. It'll stop the pen, and I personally recommend to click erase all. You can click on the colors! And when you click the X in the top right corner of the screen, hold it down for a minute. And [hopefully,] the pen will stop. And when you hold down the pen, drag the cursor around the screen to where you wan't it! {the end,} idk. By the way when you start, it matters where your mouse it.
Credit to GreenwindCat for showing me how to make the thumbnail.