Please be more specific than won’t start. The more information you provide the better advice that can be provided.
Types of info
Starter turns and spins engine but engine will not fire
Starter turns but does not spin engine
Solenoid clicks but starter dies not engage or turn
When ignition key is turned to start, nothing happens at starter
No voltage at starter solenoid when ignition key is turned to start
No voltage at the main starter terminal from battery
All of these and more fall under the general statement if ‘won’t start’
