No oil pressure stop engine ASAP

My car has been sitting idle for months and when I took it out for a drive today the light came on the said to stop the car as soon as possible. Can anyone give me some advise on what I can expect? I know nothing about cars and do not want to be ripped off.

 

First off, have a look on the floor under the car and see if there are any oil stains there - this is a quick way to see if there have been any problems and leak outs, while the car was standing idle - it would help if you find any, to locate which oil and the leak problem.
If there are oil leaks, rub a finger on the spot and smell it, if it is black and has an oily smell, it is probably from your engine. If it is red, then it is probably from your gearbox or brakes - but don't touch your car paint with it because it might be the stuff which acts like paint stripper - it's OK on your hands, but not on your car's paint.
I suggest you check the engine oil in the sump, via the dip stick, before you start your car again and top up with engine oil, if the dip stick indicator shows the engine needs it - then try again.
If you have the correct amount of oil in your engine, then I would think the problem might be at the oil pressure switch, which might be malfunctioning - this is a wire from the engine block which goes to the instrument panel on your dashboard.
Check the water in the radiator - usually the only way you can do that is to look in the overflow plastic container, which is connected by a hose to the radiator, my radiator is a sealed unit as yours probably is - you should have water or green stuff, up to the line on the side of the container, mounted in the engine bay - if you need to top it up, use distilled water or the green stuff - do not use tap water as tap water is acidic and will rot all aluminium parts of your engine over time - the stuff you should use to fill your electric iron. Woolies, K-Mart or your local shop should carry, 2 litre or 4 litre bottles of the stuff for around a couple of $.
When your car engine is running and up to pressure, have a look inside the bonnet and under the car for hose leaks.
NEVER take the radiator cap off a hot engine, because the cooling water which circulates the engine via the radiator is under extreme pressure and bloody hot and it goes off like a geyser and could give you first degree burns - let the engine cool down and remove the radiator cap slowly, half a turn to let the pressure out, then remove the cap altogether - best after a couple of hours, after you turned the engine off and NOT before.
As a first off, buy a can of WD40 or other electrical degreasing spray - the one you can spray around the engine, under the bonnet, to clean up any other electrical faults - your local garage, Woolies or K-mart should carry it.
If, after you have allowed the stuff to dry and do it's thing, try again.
While you are at it, check the dip stick for the gearbox and back axle, if you have one and check all of the other top up tanks are OK - brakes & ?
If you still have the a problem, I would suggest you take your car to a mechanic, or get a call out service, to repair your car where it is standing bite the bullet and pay the repair price, because repairs should be a lot less than a new car - if second hand or not.
Whatever you do, don't drive your car while the light is on - get it repaired first.

Richard