Why learn to touch-type?
When you type with one or two fingers, you have to look at the keys, then the screen, then the keys again. It's slow and tiring.
Touch-typists keep their eyes on the screen. Each finger knows its own keys, the way your feet know the stairs at home. With practice, typing becomes quick and smooth, and you can fix mistakes as you go.
In Grade 4 you will begin to touch-type. Don't worry about speed yet. Correct fingers first, speed later.
Finding home row without looking
Run your index fingers along the middle row until you feel the little bumps on F and J. Left index finger on F, right index finger on J. Now let your other fingers fall into place: A S D F on the left, J K L ; on the right. Thumbs rest lightly on the space bar.
After every key, your finger goes back home.