I would definitely recommend getting Nutri-berries, you can get them on amazon or at your local pet shop they are amazing for training as they are mostly pellets and most birds love them. Then I would recommend doing check point training while in the cage to begin with, here is a great video for that:
that's what I did with my guy and it worked wonderfully and will help him come when you call him. Also, I wouldn't just try to get your baby to step up so soon without positive reinforcement, have a treat in one hand and lure him to step up and praise and treat him when he does, this builds trust. When he bites you and it isn't the tiny bite to make sure your finger is stable before he steps up but a mad bite where he is backed up, butt up and aggressively coming at you first BACK off, read his body language and respect it. Walk away, grab a treat, and try again in 30 seconds. If he does manage to clamp down on you, push gently into his beak, don't pull away or freak out, pushing into the beak (again, gently), they have to release because you knock them off balance a little bit, it's worked wonders with my guy. Eventually you'll work up to a place of trust where you can let him nibble your fingers and hands and let him preen your fingernails and know that he won't hurt you, and you can reinforce that by saying "good boy, gentle, nice, good boy" as he does it. I would also recommend to never let him nibble your ears or face/lips, even though it is cute everything you let them do you are training them to do, and even when they are gently preening you they don't understand how hard is too hard and will bite down pretty hard thinking they are just cleaning you.