Since you are buying your first car, that too in used category, i would suggest that you take a good friend who knows about cars and a recommended mechanic with you when you go to see the cars you have selected. This way you will be able to learn and find a clean car, although you could get a nice & clean one in this budget. If you check yourself then you could ask for its maintenance history, any minor or major accidents, conditions of tyres, suspension, paint etc. You should also check the interior thoroughly like switches, windows and seats. Make sure to check all the corners both inside & outside of the car so you could see how well has the owner taken care of it. Take your time when buying a car as it could turn out to be a pain in the ***.