great advice above although I think one was forgotten. Go at their pace not your own
remove all ideas you have of pets, a bird is not a dog or cat and you have to earn their trust. Some people will say they're like children and in some ways they are but do view them as nothing but a bird, one of the most intelligent on the planet to be specific.
just sit by the cage and talk to them, I'd avoid looking at them during this time, remember we are a predator species and our face alone can be scary for a bird and be prepared for a long time in getting them used to you, they live for decades so a couple weeks at the start is nothing compared to all that time being happy friends