i'm getting a car soon

i have $7k in all to spend on a car, and a sound system and whatever mods i put on it


so i'm thinking about going to a car auction soon, and putting down $3-$5k on a car

i've thought about 4-cylinders etc. as they're pretty cheap and last awhile


any other ideas, this will be my first car. So it cant be something too pricey to insure, but i want something that wont have trouble getting up hills etc.