Lou012

We got a new dog about a month ago. It is a miniature pinscher. It is a chocolate and tan mix and it is 6 months old and it is a female. Well, whenever we have any company, go anywhere with her, or a new person comes, she barks and throws a fit. It isn't just a minute or two either. She tries to bite, barks, growls, and even runs at them. We have to put her in a cage or in a room. She is fine though when she is with us and seems like the sweetest dog in the world. We don't want to give her away, and we don't want to send her to obedient school because any one around here is going to be a lot of money. Is there any way to help fix this or do anything to help without spending a ton of money?