I'm sure you'll get lots of various responses to this questions. I've heard this question posed before and I've seen recommendations range from small birds all the way up to macaws.
Anyways, IMHO, ...... if a person has never had a bird (parrot) and has not been around them a whole lot I would have to say maybe a Cockatiel. Why? ...... Well, with a 'Tiel they are geneally a nice bird. They don't have intimidating hook bills like a 'Too or a Mac. "Tiels also are NOT oboxiously loud like Amazons, "Too's, and Macaws. 'Tiels are not as messy as Amazons, "Too's, and Macaws. These are all things non-bird people seem to have issues with or need getting use to as first time bird owners.
Can a new "Bird-Nerd" get a large parrot off the bat? Yes he/she can, but the goal here, IMHO, is; 1) For the bird to have a "forever" home. 2) Help foster/mentor a new person into the bird keeping hobby with a better chance of "success" in the long haul.
Good luck!