Remove your starter cover and take a test light , touch it to the small tab of the starter solenoid . Press the start button to see if the test light comes on. If so, your problem is in the starter . Remove the small wire and try wiring a starter button to same terminal and to 12v at the battery cable portion of the solenoid. If you get the same results , it's time for starter repair.
If the starting motor works , you need to go backward into the start circuit.