Thanks for the replies

Sammy eats anything we give him. I haven't seen him turn down any food yet. The U2, on the other hand, is very picky. He won't eat most things, but I keep trying. It took me a few months to get him to eat bananas.
Amazons are apparently prone to obesity, and I can definitely see why; like I said, he eats anything you give him. And then he just sits on top of his cage all day so he isn't getting much exercise. My U2 runs all over the house, chases things and bounces all day. So, there's a big difference there. Eventually, he will need a suitable travel cage since my grandmother lives three hours away and we take the U2 with us every time we go. We also like taking the U2 to the parrot refuge to visit now and again too. The lady who gave us the Amazon never took him anywhere other than to the vet. So the cage that she brought him to my house in is a small parakeet cage. It's fine for short trips, but I wouldn't want him staying in it for long periods of time. The food that she had been feeding him, she said she got from a pet store. I might see if I can't find it while looking for a travel cage for him.
I've been told that Amazons have/produce a very distinctive smell, but I don't know what this smell is and I haven't found anything about it anywhere either. When Sammy was brought to us, his whole cage had (and still has) a smell to it. It needs to be cleaned really well since it looks like it hasn't been in a while and there's bits of dried food and whatnot stuck all over it. The only way that I can think to describe this smell is to say that is smells sort of like urine. It's definitely not a smell that I'm used to. It reminds me a lot of ferrets; they have very distinctive smells about them too and you can't wash it off. This smell is sort of similar but not the same. I just don't know if it's coming from him or if the cage just needs to be washed off.
I can walk up to Sammy's cage and he runs up to the front of it and starts clucking like a chicken. He sticks his foot out, lets me pet him and even lets me pet his back. He'll just about let me pet him for as long as I want to stand there. He won't let anyone else and whenever someone else walks up to his cage, he goes and sits on the back of it. We've had him almost two weeks and he hasn't bitten anyone. He does like to chew on my fingers and he growls when he does this, it seems mostly at night. I have to just about wrestle with him to get my fingers back but he doesn't hurt me.
Something else that I haven't been able to find out is how dusty Amazons are or IF they are. Cockatoos are known as being "Powder birds" because of the dust that they produce. They say not to cover them up at night because they can choke on their own dust. The only time that I'll cover Krystal's cage is when he's in his travel cage and he sleeps upstairs in my bedroom at night, and even then, the back of it is left almost completely open. The reason I do this is because my brother's kids are here every other weekend and they sleep in his room. He sleeps with me in my room and I cover his cage mostly for me, in case I end up having to get up during the night, that way I won't disturb him and he won't see me up and think, "Oh good! You're up! It's playtime!" at 4:00am. And also when we spend the night at my grandmother's house because he sleeps in his travel cage in the same room as me there too.
We're hoping to be able to move Sammy into Krystal's room to sleep at night by Thanksgiving, which means that when the kids are here, he will also probably be sleeping in my room with me and Krystal. If that happens, I will probably be covering his cage at night too.