If you are having trouble with the parts library, take a look at this topic:
I believe there is a FAQ link in this topic, maybe reading that can clear up some of your questions.
Speaking of questions…
Have you uploaded the parts library to your fusion 360 account’s assets folder? (you have to do this through the website – or, at least, this is how I did it).
Unlike Inventor Pro, fusion 360 is largely web-based, so if you haven’t uploaded the parts to the cloud storage provided to you, then It may not work as expected.
Regardless -
We can help you a lot more if you provide specific details about what kind of issues you have been experiencing.