Conures are a great beginner parrot bird. Green cheeks tend to be less aggressive and quieter, but you could also find a nice Sun conure, jenday, etc. They can learn to talk, maybe not as clear as a cockatoo or African grey, but they are easier for beginners. They are smaller, do not have as hard of bites, are less likely to have behaviour issues. Keep in mind that parrots require a lot more attention than cockatiels, so do be prepared.

African grays are the best talking birds. The are a bit smaller than a cockatoo though.

I would prefer one that talks.

I help my grandma out with her cockatiel a lot and I have experience with birds so I know what I'm doing.

We don't want something really big but about the size of a cockatoo.