2 year old not listening

My 2 year old will not listen at all. He's almost fallen off the couch multiple times and is constantly throwing things. What tips do you moms have to help him listen so he doesn't get hurt. Before having little brother it wasn't as bad because I could get to him faster and catch him now anytime I'm nursing I just pray he doesn't fall because there's no way I could catch him before he hit the floor