jokersxf, Seeing as you do not know history of your car I suggest you remove the plastic cowl that sits below your windshield. You need to take both windshield wipers off and there are screws inside the engine bay at the base of the cowl you remove to get the cowl off. Careful as there are the water hoses for the windshield cleaning and some wires in there that are connected to the cowl, but they can be disconnected and the cowl lifted up out of the way. Once you have access to the area under the cowl you will find drain hoses which are suppose to discharge water down out of that area to the bottom of the car. Those hoses often get plugged with trash. When they do not drain properly water flows into the car on the passenger side through the large air inlet for the A/C and causes a number of problems. Under the carpet on the passenger foot well is the amplifier for the radio ( you mentioned problems with your radio) and also a air bag controller and the Transmission Control Module (TCM). It is possible that that the TCM has been compromised from water getting in there caused by the plugged drain hoses. There are four drain hoses. One on each side of the car and two in the center.

Easy to lift the carpet and inspect that area; disconnect the TCM electric contact connectors and inspect for corrosion.

If you do remove the cowl and clean out those drain hoses I recommend you disconnect the wiring from the siren ( it is located in the center of the car also under that cowl) as the internal batteries leak and can cause a number of problems. NOT saying that siren is related to your non start situation, but it has no purpose if it doesn't sound when you push the panic button on your FOB and does not effect the car in any way when disconnected. Once your current problem is corrected you can replace the siren with new or continue to drive with it disconnected as I have done for years.
GOOD LUCK