Olds bravada

Battery terminals & terminal wires may be corroded, burned, loose, otherwise no good, bad frame ground from the negative cable or bad positive to starter. Is starter turning it over? If not check/test starter. Try jumper box to crank it, I have purchased Brand New Batteries to get home with that had little charge and needed charged before it would crank the car or jumped to let it charge its battery up. But like said above we need more information in-order to help.