My car wont and ive changed the starter and the battery and now i have to push start it to make it run

If you have ensured that the battery is fully charged and able to take a load, and the starter is known to be good, and all cables are secure and free of corrosion, the next thing I would look at is the clutch switch. If your vehicle does not know the clutch is engaged, it will not allow the starter to crank. Test here next.