This subject has been covered many times... since you are a newbie here I'm sure you haven't seen them. Next time you have a question, it's sometimes easier to just do a search in the forums and you can see if the topic has been covered before...and then if you didn't find the answer you needed you can come back with a question. Saves time. Just a friendly FYI!
Now, to your topic since you've already got the question out there, here is what I've learned. Yes, you can put a fondant cake in the refrigerator. If you don't have to don't. But if you do, put it in a box first and then cover the box with plastic wrap or a garbage bag and then put in the fridge. When you take it out take the bag off but let it come to room temp while in the box. It's the humidity that causes the condensation. But even that dries after it's been out for a bit. I don't cover my cakes with fondant, but I do use a lot of fondant detail and I really haven't had a problem with it being in the fridge. I keep mine in there because I use all butter BC and I like to keep it hardened.
And you should never put any kind of cake in a refrigerator that has strong odors! I use my garage refrigerator. It stays fairly empty and nothing in it has any odors. HTH!