Crystal and Chantel got it covered!
One thing I'll add is that medical issues can be quite costly and stressful with them. They cannot go without eating because the digestive tract will completely stop moving and they will die. You have to catch it right away. My first chinchilla passed away a few months ago because of that. I did catch it right away, but even with a week in the hospital, hand feedings, medications, etc. he still passed away.
As for personalities, they can really vary. My chinchilla that passed away LOVED to be scritched behind his ears, didn't mind being held and loved being out of the cage to play. I brought him home when he was a baby.
I brought home a new chinchilla a few months ago. I adopted him from someone who was getting rid of all their chinchillas. She didn't know his exact age, but probably around 3 years old. He is hands-off. He likes me, but doesn't seem "attached" (likes me because I bring food and toys!) and he doesn't like to be touched. And I cannot hold him. And he does not come out of his cage. I can leave the door open all day and he will never come out. He obviously did not have that kind of life before he came to live with me.