Press the green flag to start, then click on the color you would like to choose, press and hold to draw. You can also click a stamp, and then click anywhere on the screen to stamp, or draw with the stamp--that's really cool!--. Press and hold p to change the pen size (1 to 100). You can also click the eraser or pencil to switch tools. Also make sure you're only touching the color/stamp/tool you want to switch to (sorry about that, it's the best I could do!). And also press c to clear.
This was REALLY hard to make, so if you remix it, please give me credit in the notes and credits section. Thanks! If your having any trouble drawing, just comment below. I'll get back to you as soon as possible.