l have no money but l dont wanna ruin my 2004 pt cruiser with 50,000 miles on it. l have no money and l havent had a tune up in a year. What are the absolute necessities l need to have done to my car that are most important besides an oil change.

There should be a maintenance schedule that came in or with your owner is manual. Follow that and you will (probably) be fine.

yes you need a Oil Change

but this is a list of a few things what should be replaced after 1 year.

New Spark plugs
New Spark plug wires
and change your air filter and
PCV Vavle

good luck
hope this helps

have your Coil tested at the parts store they do it free

If you're broke, make sure you get an oil change and a new air filter. If you're lucky, you will have a friend who can do it, and you will just have to pay for parts.

Otherwise, go to one of those chain quick oil change places. You will know the cost upfront, it usually does not cost too much, and they will top off all your other fluids, too.

A cruiser does not need a tune up (plugs/wires) annually, you should change the oil every 3-5K but that you can do at home for about 10 bucks. Check your air filter monthly. hold it to a light and if there are spots that you can not see through change it.
Do that and check the fluid levels
Engine oil
Transmission fluid
Radiator coolant level
Washer fluid
Check the belt for cracks
do this weekly and that should get you through

Cooks gave you good advice. I've rarely had ''tune-ups'' on my cars - just oil changes about every 5000 (you really do not need to do it at 3,000 - check the owner is manual) and whatever repairs of course. l had my 1994 Camaro for 7 years and put 185,000 on it. My 2001 Sebring has 132,000 miles on it and still runs well.

Making sure you change the oil and you do not drive the car if the oil is low is probably the single most important thing you can do for your car.