Ive been wanting to get a dog, But I have always owned just cats, Is raising a dog difficult? 
No, actually they are kinda friendly, I had a Yorkshire Terrier and he was nice
Arent Yorkies tiny dogs? I heard those are easy dogs to take care of, Whats owning one like? 
Yes they are relatively tiny their maximum size is like 8 to 9 inches. My dog was friendly to everyone, every neighbor knew who he was