Press left and right arrows to turn the spaceship. Press the up arrow to propel the spaceship in the direction it is facing. This is a great starting point for a game of your own!
My favorite project on Scratch is Asteroids by @Mr_Hunter. It's slick and well written. My project is a direct copy of his spaceship and thruster sprites & scripts from that project. I'm using this to learn how it works and pass on to the kids I teach. Big thanks Mr_Hunter!!!