I want a baby chick and i was wondering if i could leave a store egg our in the summer's warmth/ a warm place and let it turn into a baby chick.. does it really work???
No. In most (all?) places that sell chicken eggs in quantity, the eggs are not fertile. For that, there needs to be a rooster involved. The hen that laid your egg doesn't hang out with roosters.
Your best bet is to acquire a few fertilized eggs from a farmer who keeps chickens. You can also buy fertilized eggs online, just search for "fertilized chicken eggs for sale".