Press space to start. Use the left and right arrow keys to move the pad that keeps the ball from touching the red line.press space to reset the pad's position. You can use TURBO MODE(Shift+Green Flag), but it is veeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeery hard!!
One thing about scratch is that all you need is a brain and creativity to make a project. If you check out other peoples projects, you can get ideas for your own project.