First Love Achievement
Purchase your first car from the AutoshowGo to Horizon Mexico in the bottom left corner of the map and buy a car. Buy the cheapest you can get, because for the most part, all the cars you'll ever need and more will come as race rewards or from the Wheelspin and Super Wheelspins.
Alternatively, you can hit start, go to the 'Cars' tab, and the click 'Buy New & Used Cars' and you're transported straight to Horizon Mexico. Use this as a free fast-travel whenver you want as well too, by the way.