Your inexperience in buying a car makes you a prime candidate to be taken advantage of. First, when you buy a used car, there are no "do-overs". Once you buy it, you are stuck with it, problems and all. You need to make sure the vehicle is mechanically sound. If you don't know how to evaluate the mechanical condition of the vehicle, take someone with you who does - or take it a mechanic and pay to have them evaluate it. You need to make sure the person selling the vehicle is the owner listed on the title and that the back of the title where a sale is recorded is not already filled in. Lastly, do not trust anything the seller tells you. They can tell you it's the greatest car in the world, in order to sell it. If it's a piece of junk the seller isn't going to tell you that.