Same thing happened to me a month ago. But a few months earlier I saw the contacts on plug terminals had corroded when I was replacing turn signal lights, so having an idea the starter switch wires might be corroded I shook the wiring harness. Then knowing selenoids can stick, I then hit the starter with a hammer, it started!,Oh well, it still is fine. You could have many simple things wrong like poor conections or a bad starter or selenoid, or battery. Unless you do a load test you wont know if the battery is good, and a starter amp draw test will indicate if the starter is worn and pulling to much juice. Id start with the battery, try a good one, jump it, if it starts its the battery. Then try the hammer, or a piece of wood to hit it.