Press the green flag at the top right to start. Press the space bar to go. use the left and right arrow keys to turn (if you hold down an arrow key, it won't keep turning). Before pressing the space bar, select the color of your car by pressing the number keys 1-7 (make sure that number lock is off). Press 0 to retry from the beginning.
This was my first project. I had help from wikihow: https://www.wikihow.com/Create-a-Racing-Game-in-Scratch. it was VERY helpful!!!