[mrlmd1]

"The headlight is bright" -- does it stay bright when you hit the starter button?, or does it get very dim when you do that? There may be enough current to light up the light but not enough to kick over the starter.

"I checked the battery" -- What does that mean? Did you measure the voltage at rest or did you do a load test (which is the only way to measure a battery's condition)? How many volts did you measure at rest, and how low did the voltage drop, if any, when you hit the starter button?
Resting voltage across the battery terminals may not tell you the capacity of the battery.

Those answers will give you and us a clue about battery status and connections to the starter motor when you hit the button. It gives us a better place to start from when you ask a question. So take another look, measure the voltage before and during hitting the button and come back again. If the light dimmed significantly and the measured voltage dropped considerably when you hit the start button, your battery is at fault. If the light did not dim at all and if the battery voltage did not drop at all when you hit the start button, then we have some electrical problem we have to sort out, as no juice is getting to the starter motor. Understand what I am trying to say? We need some more information from you to proceed in an orderly fashion instead of just spouting out multiple possibilities.