Depends on the use of the car. Are you going to just cruise around? If it's something you're going to have to drive far like back and forth to school or college in the future, Gas mileage is a big factor. You don't want something slammed on the ground if you live where you get a lot of snow. You don't want low profile tires if the roads in your area are bad. You can bend or break a wheel on potholes.
The biggest factor you have to consider at your age is INSURANCE. You might have a car you love but the rates could be outrageous.