1. Check the battery. Make sure the battery is properly connected and has enough power to start the engine.
2. Check the starter solenoid. The starter solenoid is responsible for engaging the starter motor with the flywheel. If the solenoid is not working properly, the starter motor will not be able to engage with the flywheel and start the engine.
3. Check the starter motor. The starter motor is responsible for turning the engine over. If the starter motor is not working properly, it will not be able to turn the engine over and start the engine.
If you have checked all of these things and the starter is still not working, you may need to take your car to a mechanic to have the starter repaired or replaced.