Website Error Message Needs Fixed

My website is all of a sudden producing an error message when anyone tries to visit it and I am not sure why. I need someone to see if they can correct this for me ASAP. Let me know if any other information is needed to get started. 500 Internal Server Error The server encountered an internal error or misconfiguration and was unable to complete your request. Please contact the server administrator and inform them of the time the error occurred, and the actions you performed just before this error. More information about this error may be available in the server error log. Apache Server at [login to view URL] Port 80