Okay kiddo, so when wrestlers are in a match, sometimes they act like they are hitting each other really hard, but they are actually just pretending. This is called a "shoot." It's like when you play pretend with your friends and you pretend to hit each other but you don't actually hurt each other.
Now, a "shoot" can also mean when wrestlers are actually fighting for real. But that doesn't happen very often because wrestling matches are supposed to be for entertainment and not for hurting each other. So when people talk about a "shoot" in wrestling, they usually mean pretending to hit each other really hard.