i put my car in gear today and it said service. but then in the yellow square above it said OK! so.... what does that mean?

 

it means u have to get it checked out to make sure everything is fine (ie., routine check-up).
If you service you car yourself, and you know that ur car is fine.
Then you can reset it yourself.

It's quite easy,
Turn off the ignition
Press and hold the button on the left hand side of the display while turning the ignition on.
Service oil or Service Car will be displayed.
Press the left stick to chose if u want to reset the timer of the service oil or service car.
Once u've selected which one you want to reset.
Pull out the button on the right side of the display until the service prompt is cleared.
The display should now read ---
Turn off the ignition and start your car, it should be cleared.

If the above procedure does not work, outlined below is a alternative procedure.

With the ignition off, push the right button.
Turn the ignition on and then pull the left button.
This should clear the warning message


Hope it helps!