The check engine light is on
Well, that shows the CEL is working. Now take it in, have car repaired before it fails you completely.
Okay thank you, so I need to take it in before driving it anymore?
If it is blinking do not drive it. If steady you could take it to Autozone and have the codes read and post the codes here, format is P0123, and we could give you some ideas on what the problem is.
Could be as simple as a worn out gas cap. But on a 15 year old car I suspect it will be something else. There are parts and sensors that have excised there life expectancies and will need to be repaired or replaced.
You do not need a dealer. An independent shop can normally do the work.
To find a mechanic you can start with mechanic files on the cartalk.com home page. You can ask friends and coworkers, check yelp reviews. Even a Facebook page for your community might guide you.
One thing, a shop may charge $100-200 diagnosis fee. Some will waive the fee if the work is performed by them.