I have been thinking about getting a Yorkshire Terrier as a family pet! I have researched TONS, believe I know how "big" they think they are

Anyways, I was wondering if there is one thing that has helped you most with your Yorkie, or anything that I REALLY need to know about them. I know how very very fragile they can be, and am willing to do whatever it takes to keep one safe, if I get one. So, is there anything you guys think I should know FOR SURE before getting one? Thanks!