I connected my battery wrong on my silverado 07 and it did spark, but now I connected a raid way and now won't start, I open the key and doesd du nothing not ivend the lights turn on

. Check all under hood and under dash fuses with a test light or multimeter.

. Check alternator.

. Check PCM--it may be fried.

Turn your key forward, if the "service engine soon" light doesn't come on you fried your computer. I know this cause I did the same thing.