Mechanic Job in El Paso, Texas

I'm an army Vet who is in urgent need of a mechanic! I was left in El Paso with a 2001 Toyota Corolla with over 200,000 miles on it. Less than a week ago, I started encountering issues when starting it. When i tried to start the car it would make a ticking sound when I turned the key in the ignition. Not knowing anything about cars, I took out the battery, took it to autozone to run diagnostics, and get it charged. When I brought the battery home it was 90% charged. However, when I put the battery in its prospective place then i began having issues with the car staying on. When I put the key in and turn it, the car starts, but maybe 3 seconds later it starts to rattle and powers off on its own. All the other components and parts of the car like the power windows, headlights, turning signals, and the radio, all work just fine. I just cant keep the car running. I DESPERATELY NEED HELP AS SOON AS POSSIBLE!!!!