Advice for a wannabe tiel owner

I'm thinking about adopting a cockatiel As of right now I'm taking care of a little sparrow unable to fly from a friend of mine It awakened some bird love inside of me, and I did find cockatiels really cute and easy to get

So any advice about them, on a daily basis, what should I know before hand, what not to do, what should I prepare for, etc Would be very appreciated, thanks!