The following functions are available during the keyboard control is active to operate the bus:
If your bus is damaged by a collision, you can get it repaired with the "Repair" button in the game menu.
If you get stuck, you can place it via free map camera [F4] with a left-click on the map, preferably on the road.
But since you should only go straight on your feet first, you should not need these tools.
Continue driving straight ahead along the road until at right hand side is the gas station BP. Keep straight ahead.