My 9 month puppy wont stop getting into stuff?

I have a german shepard rottweiler mix and hes a pretty medium sized pup so he can get onto beds and furniture so its easy for him to get things. Usually whenever we come home their is slippers, stuffed animals sorta torn but not really bad, their was plant dirt messed up but he eventually stopped and usually my mom is the one that catches him and she goes to smack his butt and says "No" but yells at him. And i know its bad for him to do this but im an animal lover so its hard for me to see a dog get smacked, i even told her yelling isn't going to do anything. He tore apart most of his chew toys i just think hes bored and cant do anything. What could we do for him to stop?