I don't know why but I seem to be really nervous of my 14 week old pet Rat? What should I do t trust him?

I wouldn't be too worried about him biting you. I've only been bitten once, and that was only because I had something tasty on my lip and she wanted it xD. But that was kinda my fault. Anyways, trust your rat, he's probably all jumpy because he's young and hyper?