Welcome
. Change the oil, change the coolant. Put a bottle of fuel injector cleaner in the gas tank. Then drive it a while and then do the cheap headgasket test.
Do the cheap test for headgasket leak.
Here is a cheap quick way to test the headgasket.
Fill antifreeze to the brim on recovery tank (leave cap off). Remove all spark plug wires. Remove all but one spark plug and have someone crank the engine. If the antifreeze bubbles over, there is leak from that portion of the engine (or cylinder). If not, go to the next cylinder, and then the next.... Note, it could be more than one area or more than one cylinder. Good luck.
My car was sitting for about a year but was started a couple times during that period. I drove it a couple times for about a half hour 3 times each and it always seemed fine. Now there is black liquid coming out of the exhaust which looks and smells like oil. There is also white smoke coming out of the exhaust while the car is running even after it has been idling for about 20 minutes. 
I checked my oil and other fluids and they are all fine. The car use to drive fine those couple times i drove it but now it is doing those 2 things. ALso even after letting it idle for a while then when i rev it a little, the rpms drop real low in idle after i let go of the gas and sometimes it dies out. I really need any help i can get about this problem. Again this is on a Automatic 1998 Ford Contour SE V6 engine. I called a mechanic and he said it sounds like a ring might be sticking in the engine from sitting (but doesnt seem to make sense because it was driving fine even after sitting the couple times i drove it) or else he said it might be a blown headgasket. 
I need to find out what i can check on my own though because the car has no plates, insurance and i have no license at the moment, therefore i cant drive it anywhere to get it looked at. Thank you 