What a cutie!
I have an African ringneck who doesn't fly. I think for birds like ours that are VERY suspicious of hands, a lot of them will be comfortable on our shoulders or arms but will take a long time to step up onto bare hands. I'm pretty sure that if Cotton could fly, he'd be a shoulder bird all day long.
I've had Cotton for two years now, and he's just now at the point where he will target a stick all over his cage. We work on "taming" tasks every day. Rarely he'll reach over my closed fist to touch the target, but he will absolutely not come close if my hand remotely looks like I could touch him or ask him to step up.
Have you tried using a perch for him to step onto instead of your hand? Or maybe your arm, with a towel over it? Cotton has zero body feathers so it's easy to knock him off balance, so I've been playing with different ideas of perches he could step onto for me to move him. When he's fallen, I've used a little wooden ladder and that works pretty well but we're still working on re-training that the ladder is a good thing and not a scary thing that chases him.
My biggest tip with ringnecks is to just keep trying, 5 minutes or so every day, and also if you can, video your training sessions - their body language is so subtle sometimes, it can really help to watch back and see *exactly* when they stopped, or leaned back slightly, or flattened their feathers slightly. I worked with a trainer last year for Cotton and that tip was a game changer. I had to break everything down into the tiniest steps, which was a lot harder than I thought it would be, but now that I've practiced that for a year it's easier to keep making progress (slowly, ha).
Cotton is VERY good at training ME when he doesn't want to do an action or when he's nervous about it - so I try to stay at a level where if I'm going to ask him to do something 10 times, I want him to do it pretty easily 5-6 times, then I ask him to go a little further, then again, and if he refuses I turn around for a moment, then come back and alternate easy thing with hard thing. Usually he surprises me and I'll get one rep where he does the hard thing, but then he immediately refuses to do it again for a week or two
so I always end with something really easy that he likes doing (there's a section of his cage top he likes running along to touch the target).
Basically I try to have a balance of successful repetitions with him pushing himself through the thing he doesn't like, without him getting frustrated at the whole process, and without accidentally rewarding him for telling me no
As far as timeline for us - it was a full year before he would take treats from my hand (only from my fingertips). Another six months (and working with a trainer) to reliably touch a target stick. And now it's been another six months of slowly pushing him to stay closer to my arm.
