Q: My coolant reservoir is empty and coolant is splattered over my engine

Driving a car with "zero" coolant will destroy the engine within minutes. Even after a coolant leak, though, you have some coolant in the engine and water can sometimes be added to enable one to drive a "short" distance as long as you observe the temperature gauge on the instrument panel and do NOT operate the car, even momentarily, in the RED (overheated) danger zone. But, the problem is because we do not know the nature and extent of the coolant leak that you have, once you add water (or anti-freeze) it is hard to predict if it will leak out quickly, thus quickly leading to an overheating situation once you depart, and possibly leaving you stuck between home and a service facility. When the car is stone cold (if you open cap when engine is hot you will be severely burned), you could try removing the radiator cap, adding water, re-installing the cap tightly and see if the car will idle for 10 minutes without overheating and without coolant leaking out. If the car seems "stable", you could "try" to make it to a shop.

As far as what’s wrong, you have a leak, the origin of which is usually obvious once a mechanic makes just a visual inspection. There are so many places a cooling system can leak: radiator cap, water pump, radiator, hoses, and so forth. All of those are easy to deal with though and so you needn’t worry. It will be least risky (in terms of potentially overheating the engine), and also much less expensive, if you have a certified mobile professional come right to your door and resolve this for you. If you desire, do follow-up with YourMechanic and request a cooling system leak diagnostic during which the Mechanic will let you know exactly what the story is. If I can be of further service, or you have additional questions, please do not hesitate to contact me.