I'm not sure what you mean by a training diet. People who are training their birds for free flight will often give their birds a very restricted diet so the birds are highly motivated to work for training rewards, meaning that they'll want to come to the owner when called to get a bite of food rather than flying away and never being seen again. There's a term for this technique but I can't think of it at the moment. "Food management", maybe. It's not necessary for ordinary taming and training, and not a good idea in general. The whole point of the technique is to make the bird feel like it's starving even though it actually isn't, and we don't want our birds to feel like that. The bird might actually starve if you don't do it just right.

For ordinary training it's helpful if the bird is a little bit hungry, which you can arrange by taking away the food an hour or so before the training session. If your training reward is super delicious, it's not even necessary for the bird to be hungry. They'll want that treat anyway.

I am wishing you great luck on taming! I got Shodu, April, and Moon to step up on my hand. I just haven't practiced for a while, so they are kinda scared of me now.

Now, Beck is very distracted by the cockatiels. All he wants is to be with them. Do I need to move the budgies cage away from them?

You could always use the cockatiels as a training tool. Put them on you and encourage Beck to join the party!

Works everytime with Georgie and Marshmallow.

That is genius.

For extra credit, serve millet spray or some other lovely treat at this "every birdie get on me" party. Be prepared to brush seed hulls off your clothes afterward lol.

Very true! Socialising sessions leave you a mess.
I often need to change my clothes afterward

That looks like graham cracker mess lol. That's a popular treat with a lot of birds.

Okay now, in order for Beck to jump on me, I have a feeling clipping his wings may be the better route to go, but he is not confident enough to stay anywhere near me. I remember I trained Jail Bird to easily accept my appearance by putting some millet spray on the arm of the couch with me laying there. She was clipped and LOVED to eat, so that was easy. But I like to see Beck fly. And he doesn't like to cooperate when he can fly.When he was one of my first birds, his wings were always clipped and he would be still and I could touch his feet. One day he even jumped on my back. That was very exciting, but that was a couple years ago. I would feel guilty clipping his wings, but he is a free spirit and he could be even more free if he learns to trust me. I try to avoid clipping if possible, but I can do it... I don't know.