Hi sorry that you don't have these facilities about where you live - a lot ofplaces don't.
Please don't be scared of your puppy - you and your puppy will be fine all that needs to happen is that you are both working to the same agenda. Your puppy doesn't mean to be mean or harmful, he is talking in the only language he knows - that is using growling,nibbling - it's like a very young child having a temper tantrum.
What I will do is send you an e-mail with specific advice on how to handle your puupy's aggression. This is taken directly from one of the best sites for German Shepherd dogs. But you and your puppy will be fine - remember to relax around your puppy and even if you don't yet feel confident, just pretend in front of your dog that you are.
Okay I will go and get the e-mail ready for you.