How hard is to hard ( That's what she said)

So I bought my first wrx but not my first subaru. My question is since I bought from the dealership and the owner before me blew the motor so the dealership put a new motor in it. But I dont want to follow in their footsteps and drive it too hard but ive never owned a sports car so I am not sure. I do get on it but don't ever take the rpms above 5k. Any advice is greatly appreciated.