When the starter fails to fully actuate, free-wheeling instead of engaging the ring gear, it will whine. Hotwire the starter to test it's getting full voltage. Replace if still whines.
Whining from an engine is never good unless you have a supercharger or blower. This is usually a sign that you have a failing component. IT may just be a accessory like the power steering pump or you may have something serious like a spun bearing.
Your battery may be low. If you can get it started then let it run for a bit to recharge the battery. Also, be sure to take charging cables with you just in case.
I would most definably have that checked out with your mechanic. It seems that your transmission has been acting up and might be possibly going out in the near future.
