Buying a used car.?

I just bought my 1st used car (92 Plymouth Breeze) and about 2 weeks after I bought it the enigine and brake light came on. The brakes are really bad now all of a sudden. When I test drove the car it seemed like it was in perfect shape. Can people do something to used cars to make them seem perfect when you want to buy them.. and then later come to find out it wasnt as good as it seemed when you test drove it??? Help...!