Aggressive and scared!

Welcome! You've hit on the key word in your last sentence-- "patient." Lots of patience will be needed, especially with a rehomed QP coming from less than ideal conditions. For now, don't insist that your parrot come out of his cage or physically interact with you. Concentrate instead on letting him get used to you and his new home. Simply sitting calmly near his cage and talking softly to him is a great way to start. It will help him get used to the sound of your voice and your body language-- and the other members of your household should do that too.
For now, it's probably best not to put hands in his cage except for necessary servicing of food and water dishes and cleaning the cage. Imagine if you had just moved into a new house in unfamilar surroundings and a giant hand reached in to grab you. That would be upsetting and frightening for you, and it's much the same for a newly arrived parrot. Give him more time to adjust and settle in and he'll probably want to come out of his cage voluntarily. You might try adding a hanging perch on the outside of the cage, just below the cage door. Leave the door open and let your parrot decide for himself when he's ready to step out onto the hanging perch. That offers him a place to sit and look over his surroundings in a place where he'll feel safe and he can step right back inside if he wants to.
You'll need to experiment with different treats to find ones that your QP will like. The favorite treat of my two parrots is popcorn-- plain air-popped popcorn (no oil, butter, salt or added flavorings). Some parrots like dry cereal for a treat. Cheerios are a favorite of many parrots. Unsalted pumpkin seeds are also popular parrot treats.
Good luck to you and your new feathered friend.