So this is my experience, so others may vary.
If they are from a "bin-o-budgies" from the pet store, it may take a long time to get tame, if ever, as they grow up in colonies, so don't expect it to cuddle up or anything. If you want that you'll likely need to find a breeder or someone who takes the chicks from the parents and hand feeds. Not that it is not possible to tame a pet store one, just a ton of work.
Took about 2 months to get one of my two pet store budgies to even step up on my finger but almost a year later, she still doesn't really come up unless you have something she wants. Her mate is older and still does not want to step up. If the bars on her head are all the way up to her nares, then it is probably under 6 months old, if it has a solid colored head, it is likely and adult. In terms of caged birds, to me they are akin to a leghorn in flightiness x 100!
Unlike chickens they are rather timid and may or may not ever eat fruit. When I was younger I had a pair who'd have fruits/veggies offered daily for over a year before I just quit because they never wanted any... just ate their zupreem pellets or seeds. The girl I have now is more brave and has tried fruit, but just doesn't like eating them, the boy won't even taste the fruit. They both however like to lick your fingers if you were eating potato chips.
Give the bird time and it will take lots of patients. If it's wing's aren't already clipped, I would do so, as a flighted bird is a free bird who can easily get injured flying into walls if it is scared of you. Start by just sitting outside the cage for the first week, then putting your hand in the cage for a week or so, then slowly getting your hand near the bird for another week till it tolerates your hand in there, and then you might be able to put your finger up to it's chest to teach it to step up. Don't worry if it just flies off, it can take weeks if not months for a bird to warm up, especially a bin-o-budgies bird.
And one more thing, I wouldn't hold it like you hold a chick around the midsection. That is likely to just scare it and make it fear your hands. You'll probably want it to learn your hand is a safe place to sit and not force it or it will run as soon as it can.
If they are from a "bin-o-budgies" from the pet store, it may take a long time to get tame, if ever, as they grow up in colonies, so don't expect it to cuddle up or anything. If you want that you'll likely need to find a breeder or someone who takes the chicks from the parents and hand feeds. Not that it is not possible to tame a pet store one, just a ton of work.
Took about 2 months to get one of my two pet store budgies to even step up on my finger but almost a year later, she still doesn't really come up unless you have something she wants. Her mate is older and still does not want to step up. If the bars on her head are all the way up to her nares, then it is probably under 6 months old, if it has a solid colored head, it is likely and adult. In terms of caged birds, to me they are akin to a leghorn in flightiness x 100!
Unlike chickens they are rather timid and may or may not ever eat fruit. When I was younger I had a pair who'd have fruits/veggies offered daily for over a year before I just quit because they never wanted any... just ate their zupreem pellets or seeds. The girl I have now is more brave and has tried fruit, but just doesn't like eating them, the boy won't even taste the fruit. They both however like to lick your fingers if you were eating potato chips.

Give the bird time and it will take lots of patients. If it's wing's aren't already clipped, I would do so, as a flighted bird is a free bird who can easily get injured flying into walls if it is scared of you. Start by just sitting outside the cage for the first week, then putting your hand in the cage for a week or so, then slowly getting your hand near the bird for another week till it tolerates your hand in there, and then you might be able to put your finger up to it's chest to teach it to step up. Don't worry if it just flies off, it can take weeks if not months for a bird to warm up, especially a bin-o-budgies bird.
And one more thing, I wouldn't hold it like you hold a chick around the midsection. That is likely to just scare it and make it fear your hands. You'll probably want it to learn your hand is a safe place to sit and not force it or it will run as soon as it can.