You might need a flashlight to locate the OBD port. It’s close to the hood release lever and it looks like a serial port for an old printer.
Manufactured between 2007 and 2012, the Dodge Caliber is a compact hatchback. It does have a reputation for transmission problems, leaky tubes, and engine problems. If this is happening to you, try reading the codes!
If you run into a problem you can’t solve yourself, bring your Dodge to a qualified repair technician or dealership. Your vehicle may even be subject to a recall, in which case your repair costs might be covered by the manufacturer.