Hi and welcome. Sorry the responses sound a bit harsh and stern. Most of the folks who have kept parrots on here a long time, like your Nana, have seen a lot of posts and spoken with a lot of young people like yourself. And believe me they are looking out for both of your best interests. Yours and any parrot you may get or adopt. The parrots, because parrots in general are loud. A few , very few individuals may be on the quiet side, but that is not a species specific trait. Most are loud 2-3 times a day ( morning, at feeding times, and at sundown) My own is loud at feeding times and around 3-4 in the afternoon. Othertimes he squacks and sings and talks a bit. However, his species is not known for quiet. I would say if thats one of the desired traits, a Cockatiel would be a chioce. They whistle a lot, not scream. Any parrot larger then that has the POTENTIAL to be loud. And parrots do not usualy start out loud. Whentheir needs are not being met ( food, water, companionship, attention, toys, a mate) they can get loud, and may get loud all the time is you dont figure out what they need. A Cockatiel can be trained to accept a harness and be on your shoulder outside. Some love to be scratched on their heads , but they are not known to be cuddly ( again, a few are). And a cockatiel who can whistle Star Wars or Addams Family or other tune is really funny. Parrots need a LOTof work and training to be the quiet, cuddly, well behaved parrot you are lookings for, every parrot needs those to attain real comapnionship with humans. What we hate on here is to hear that someone gets a parrot, and with an unexpected life change ( or a planned one, like college or full time work ) is unable to give the parrot all it needs, its starts to scream or pluck its feather or actually bite, HARD, anyone. And the parrot gets re-homed, or given to a bird society, after maybe giving its little heart to you.
And your best interest. Nothing besides loosing a child, can break your heart deeper then having to give up your parrot or even worse, having it pass away, maybe becasue of some aspect you were unable to provide. Food, good diet, medical care, an companionship. You may never look at birds the same, and your Nana's memory tainted becasue of the experience. You seem like a nice, intellegent, well spoken young person. People with those traints are smart enough to listen and heed the scar tissue of those who have experienced life lessons to be learned.
So my best reccommendation is to wait. Establish your life. Finish what schooling you are planning. Volunteer at a parrot sanctuary or avian vets office, to learn more about the different speciale first hand. And THEN get or adopt your life long parrot buddy.
Second best reccommdation - get or adopt a Cockatiel. Talk to cockatiel folks on here ( Amymybluefront is a good candidate). Learn all you can from them. And please, stay with us. We are really on your side.