In Georgia, it is the SELLER’S RESPONSIBILITY to provide a valid passing emission inspection at the time of sale if the vehicle being sold is required to be registered by the PURCHASER in one of the 13 Atlanta-metro counties. Otherwise it is the buyers responsibility.
If you live in metro Atlanta, go back to the dealer and demand they correct the problem. If you live outside of the metro area, than it is your responsibility to ensure the vehicle passes admissions. If they refuse, then report them to the state emissions counsel: 800.449.2471.
If you do live outside, then the next time you buy a vehicle, you should have it inspected before you complete the purchase. If the seller refuses to allow you to do this, then don't by the vehicle.
I do not think a law suit will be necessary in this case as the state has appropriate processes in place to deal with the dealer if they violated the law. if you live outside of the metro area, then it is your responsibility and suing the dealer will not help you.
You will need to go on to law school, where you ought to take a few courses in family law. Really, though, you don't specialise in a particular field of law until you're out of law school and into practice. Though try and focus your legal elective courses during your JD onto the family law realm.
You'll probably also have to change your major (or even school) and pursue a BA or a B.Sc. Most people who go into law take on a BA, which trains you in writing, as well as critical reading and analysis. You'll find those things useful on the LSAT. There really is no "pre-law" recommended field, just certain fields that seem to produce a large number of law students. Political science, economics and business grads go to law in big numbers, but any undergraduate bachelors degree can get you in. Don't bother with any law-related courses in your undergrad, you'll go on to law school to learn that stuff. If I were you, I'd focus on areas that would be applicable to family law in your future: women's studies, child development (psychology), family structure (sociology), etc. That'll give you a broad background to which you can apply your legal education.
And, of course, make sure you do very well in your courses, since you have to get admitted to law school shortly thereafter.
Best of luck to you! Family law has a reputation as thankless low-paying work. It's certainly not glamourous or high-paying, but it can be rewarding, particularly if you're dedicated to it. We could use more practicioners in the area.