what could be wrong

Need more information. Does it not turn over at all? Or does it crank and crank but will not start? If it will not crank, put a jump on the battery with either cables or a jump-box. If it still will not crank and you've verified good connections and power (if you can turn your high beams on and they are bright, it should have sufficient power to crank.) From there you need to look into the Starter relay, solenoid, and Starter itself. If it cranks but doesn't start, keep it simple for starters and check the Inertia Switch. This is usually located in the trunk mounted on one of the sides, or it will be underneath the passenger-front kick panel (in front of the door, where your right foot would be.) It will have a single plug coming out of the bottom, and a red button recessed on the top of the switch. If you find it, push the button down. If it clicks in, then the switch was tripped and the car will start. If it doesn't move, this isn't your problem but unplug it and reconnect it with the key off to be sure. From there, you need to verify fuel pressure and spark to continue the diagnostic process.

It doesnt even turn over. Ive taken out the starter and tested it, it works great put it back in and it wont even turn the car over. the lights work great ive tried hooking it up with jumper cables to. been working on it but just stuck because it wont even turn over.

Have u checked fuses? Or relay igntion relay