A significant part of a tune up is changing the spark plugs. This is an area where you'll need to be careful, because newer cars come with fuel injection systems. In most cases, you'll be able to remove the spark plug wires and, using a spark plug socket, remove the spark plugs. Check the spark gap of your new plugs using a spark gap gauge, and then insert them with the appropriate length plug wires.
If the car looks like this photo, then you have a fuel injection system and need to make sure you understand how plugs are removed before changing them. Check the manual or speak with your dealer.