Go to Arcade Mode and pick the options as follows:
Difficulty: Very Easy
Time Limit: Very Easy
Mirror Mode: Off
Choose "automatic" when given the choice. There are 4 laps and 20 positions. You must be in position 1 by the time you cross the finish line. The top right of the HUD has the positions. You must be careful not to hit a wall during a turn at high speeds. If you brake it's somewhat hard to control so you might consider just slowing down a little. If you do flip your car, continue on and do not go into the pit stop or risk losing. You can still finish the race with 1st in your slower accelerating car.