Click the thing you want to learn then use w and s or arrow keys. You can also drag but that's mainly for mobile. To go back to the list you press the home button(down right). If you hover your mouse over the snake thingy it will show you the link to it.
A few tutorials explaining how to do basic stuff. I'm working on more but they do take a bit to make. If you liked this consider trying out my other games!
