How do i stop my german shepherd pup from going crazy!?

We keep the german shepherd puppy out at night its 14-15 weeks old and we have a little Lhaso apso that is 10 years old and we keep her in the house. The problem is that we cant keep it in the house at night because she is an outside dog that would probably wreck the furiture and we let it in from morning to night iin half hour intervals, but when we let it in it goes mad it jumps on the sofas even when peoples sitting on it, it pulls the bobbles of the christmas tree and jumps on our fragile Lhaso apso, i un derstand that it is young but what can i do to discourage this type of behaviour as i've tried holding it for a few minutes when it comes in, i've tried verbally saying NO! firmly but not abusivily and i resorted to lastly hitting it on the nose with a newspaper which i did'nt keep doing as i thoughtb that it was cruel and did'nt see and success out of it please help!!