Depending on how old this car is it may be doomsday. Those are a lot of symptoms that don't tie together too well into a single cause and if the car is old the cost of repair may be more than the car is worth. Or not. The oil coming from the spark plug is a bad "tube seal" and is replaced with the valve gasket set, typically $200-$300 parts and labor for a 4 cylinder, about $100-$200 more for a V6 or V8. The shaking can be a lot of things (and the oil light may be related through low idle if it is only on at idle, not while driving) that come into much better focus if we know what sort of car this is. Also, make sure the check engine light comes on before you start the car (just to make sure it works) and is not on when the car is running - that is a crucial clue when dealing with the engine running badly.
Finally, back up a step and decide where this is going. It is not hard to put more into a car in repairs than the car is worth, so see what is needed. Look at the cover behind the rubber accessory belt(s) on the end of he engine. If it is metal the engine has a timing chain and is not a worry. If it is plastic it has a timing belt which is likely to be overdue for replacement, and that is a $300-$1500 cost you can't escape. If a timing belt fails while you are driving the engine stops dead and many of them suffer severe damage. For other things take advantage of freebies - brake shops will gladly do a free visual inspection of the brakes and shops that do front end (suspension and steering) work will also do a free visual inspection of the front end and shocks. It is a sweet deal all around - you get a free check by a professional (a few will try to pull a fast one, so get a free second opinion at another shop if they recommend repairs) and the shops get potential customers who probably need work done and they can provide an intelligent estimate. Once you know what you are up against you can set your course.
Oil light means no oil pressure, internal engine parts are not being lubricated. The engine likely suffered major internal damage by being run with low coolant and oil.
New engine too late for your old one and go to night school to learn about engines like how to do a service, top up the engine liquids that make it run.
There is no help for people that let things get to the point that you have.
There's no coolant and my oil light blinks on and off. There is oil coming from my spark plug. My car is not overheating though. There is barely any oil left in my car. I've had a problem with one of the spark plugs coming out in the past right after I bought it. Help? I have no idea. There's no smoke.
