Install Scratch link and connect your EV3 brick with Scratch. If you have problem watch - https://www.youtube.com/watch?v=aBPU1HKj1PQ Connect right motor to port D, left to port A. Now you can steering vehicle by arrow keys on your computer.
If you want to see how it works, watch: https://www.youtube.com/watch?v=c-k2An68bTM