After you have figured out which way to turn the crank you will need to learn to control your work:
If you learn to HC you HAVE to control your work with your left hand. I see a lot of different people check out machines. Way too many people try to sew with one hand pulling fabric through the machine with their left hand - I've seen a few try it with their right hand, too. Then they wonder why their projects look terrible. You are supposed to keep your hands in front of the needle and let the machine do the work. (I think I learned that the hard way with a sewing machine vaccination when I was about 5 or 6.) An investment in a finger guard may help set some boundaries. If you use a HC you will need to learn to sew by controlling your project with your left hand only. I learned on a HC and did not realize how much control I have with my left hand. If nothing else it is a good way to improve your sewing. The HC is good for speed control. You can go very slowly and stop anywhere you like. I have also gone about as fast as I ever want to. Then I've had kids want to 'help' and they tend to go as fast as they possibly can. There are projects I like to go slow on. The HC is wonderful for those. They are very predictable. A motor or a treadle is less predictable for speed. I am thinking my brain waves go quicker to my arm than my legs and feet.
When I was camping I was bombarded with little kids wanting to test out my HC. Not wanting a thread nest, I let them sew on paper. 3x5 or preferably larger cards and cheap brown paper lunch bags are good to learn on. I tell them they HAVE to keep their left hand in front of the needle. Here is my method and it doesn't have to be in any order:
Student puts dots on the paper bag or card - pencil crayon or marker - what ever is handy will work. The student can choose how many dots they want and put them anywhere they want. Next they sew from one dot to another dot then they drop the needle into the dot, lift the foot and turn the paper then sew to another dot. See how many lines they can make. They can also use a page of dot to dots or a maze. Those can be found on Google or from a book.
Another thing to do is to sew between the lines on a 3X5 or larger card.
Sew down each line of the card.
Sew around the edges stop and turn the corner. Dots might help there, too.
Sew about anywhere on a paper bag - then open it and look at the pattern - shine a light! But I like to let them test out curves on the paper bag. Hearts, circles, names, words, etc.
Then try piecing a 9 patch or some simple project.
As long as they are learning to control their work make it fun.