The first thing that comes to mind is to
give your Sun time to adjust to her/his new world.
They are not anything like a puppy that accepts you on the spot. Let your new FID adjust to the cage and environment first.
You should start out just talking to him from a short distance away from the cage and work your way closer on his terms not yours!!
If your Sun is a young baby this process will go much faster than if it is an older bird.
Oh yea toys toys toys. Just make sure there is enough room in the cage to stretch out his wings without hitting any toys..
Good luck and congrats..