When should I get a tune up and what does it.

There is really no longer an answer to that question. Cars have all different types of ignition systems that require varying degrees of maintenance. Most but not all spark plugs will run for over 100K. Ignition wires will usually fail even quicker these day and then many card have no wires and coil failures are common. I would say on your car expect to start replacing some things near 100K